2 * Copyright © 2014 Red Hat
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 #include <linux/delay.h>
24 #include <linux/errno.h>
25 #include <linux/i2c.h>
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/seq_file.h>
30 #include <linux/iopoll.h>
32 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
33 #include <linux/stacktrace.h>
34 #include <linux/sort.h>
35 #include <linux/timekeeping.h>
36 #include <linux/math64.h>
39 #include <drm/drm_atomic.h>
40 #include <drm/drm_atomic_helper.h>
41 #include <drm/drm_dp_mst_helper.h>
42 #include <drm/drm_drv.h>
43 #include <drm/drm_print.h>
44 #include <drm/drm_probe_helper.h>
46 #include "drm_crtc_helper_internal.h"
47 #include "drm_dp_mst_topology_internal.h"
52 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
53 * protocol. The helpers contain a topology manager and bandwidth manager.
54 * The helpers encapsulate the sending and received of sideband msgs.
56 struct drm_dp_pending_up_req
{
57 struct drm_dp_sideband_msg_hdr hdr
;
58 struct drm_dp_sideband_msg_req_body msg
;
59 struct list_head next
;
62 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr
*mgr
,
65 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port
*port
);
67 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr
*mgr
,
69 struct drm_dp_payload
*payload
);
71 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr
*mgr
,
72 struct drm_dp_mst_port
*port
,
73 int offset
, int size
, u8
*bytes
);
74 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr
*mgr
,
75 struct drm_dp_mst_port
*port
,
76 int offset
, int size
, u8
*bytes
);
78 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr
*mgr
,
79 struct drm_dp_mst_branch
*mstb
);
82 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr
*mgr
,
83 struct drm_dp_mst_branch
*mstb
);
85 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr
*mgr
,
86 struct drm_dp_mst_branch
*mstb
,
87 struct drm_dp_mst_port
*port
);
88 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr
*mgr
,
91 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux
*aux
);
92 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux
*aux
);
93 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr
*mgr
);
95 #define DBG_PREFIX "[dp_mst]"
97 #define DP_STR(x) [DP_ ## x] = #x
99 static const char *drm_dp_mst_req_type_str(u8 req_type
)
101 static const char * const req_type_str
[] = {
102 DP_STR(GET_MSG_TRANSACTION_VERSION
),
103 DP_STR(LINK_ADDRESS
),
104 DP_STR(CONNECTION_STATUS_NOTIFY
),
105 DP_STR(ENUM_PATH_RESOURCES
),
106 DP_STR(ALLOCATE_PAYLOAD
),
107 DP_STR(QUERY_PAYLOAD
),
108 DP_STR(RESOURCE_STATUS_NOTIFY
),
109 DP_STR(CLEAR_PAYLOAD_ID_TABLE
),
110 DP_STR(REMOTE_DPCD_READ
),
111 DP_STR(REMOTE_DPCD_WRITE
),
112 DP_STR(REMOTE_I2C_READ
),
113 DP_STR(REMOTE_I2C_WRITE
),
114 DP_STR(POWER_UP_PHY
),
115 DP_STR(POWER_DOWN_PHY
),
116 DP_STR(SINK_EVENT_NOTIFY
),
117 DP_STR(QUERY_STREAM_ENC_STATUS
),
120 if (req_type
>= ARRAY_SIZE(req_type_str
) ||
121 !req_type_str
[req_type
])
124 return req_type_str
[req_type
];
128 #define DP_STR(x) [DP_NAK_ ## x] = #x
130 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason
)
132 static const char * const nak_reason_str
[] = {
133 DP_STR(WRITE_FAILURE
),
134 DP_STR(INVALID_READ
),
138 DP_STR(LINK_FAILURE
),
139 DP_STR(NO_RESOURCES
),
142 DP_STR(ALLOCATE_FAIL
),
145 if (nak_reason
>= ARRAY_SIZE(nak_reason_str
) ||
146 !nak_reason_str
[nak_reason
])
149 return nak_reason_str
[nak_reason
];
153 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
155 static const char *drm_dp_mst_sideband_tx_state_str(int state
)
157 static const char * const sideband_reason_str
[] = {
165 if (state
>= ARRAY_SIZE(sideband_reason_str
) ||
166 !sideband_reason_str
[state
])
169 return sideband_reason_str
[state
];
173 drm_dp_mst_rad_to_str(const u8 rad
[8], u8 lct
, char *out
, size_t len
)
178 for (i
= 0; i
< lct
; i
++) {
180 unpacked_rad
[i
] = rad
[i
/ 2] >> 4;
182 unpacked_rad
[i
] = rad
[i
/ 2] & BIT_MASK(4);
185 /* TODO: Eventually add something to printk so we can format the rad
188 return snprintf(out
, len
, "%*phC", lct
, unpacked_rad
);
191 /* sideband msg handling */
192 static u8
drm_dp_msg_header_crc4(const uint8_t *data
, size_t num_nibbles
)
197 int number_of_bits
= num_nibbles
* 4;
200 while (number_of_bits
!= 0) {
203 remainder
|= (data
[array_index
] & bitmask
) >> bitshift
;
211 if ((remainder
& 0x10) == 0x10)
216 while (number_of_bits
!= 0) {
219 if ((remainder
& 0x10) != 0)
226 static u8
drm_dp_msg_data_crc4(const uint8_t *data
, u8 number_of_bytes
)
231 int number_of_bits
= number_of_bytes
* 8;
234 while (number_of_bits
!= 0) {
237 remainder
|= (data
[array_index
] & bitmask
) >> bitshift
;
245 if ((remainder
& 0x100) == 0x100)
250 while (number_of_bits
!= 0) {
253 if ((remainder
& 0x100) != 0)
257 return remainder
& 0xff;
259 static inline u8
drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr
*hdr
)
262 size
+= (hdr
->lct
/ 2);
266 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr
*hdr
,
272 buf
[idx
++] = ((hdr
->lct
& 0xf) << 4) | (hdr
->lcr
& 0xf);
273 for (i
= 0; i
< (hdr
->lct
/ 2); i
++)
274 buf
[idx
++] = hdr
->rad
[i
];
275 buf
[idx
++] = (hdr
->broadcast
<< 7) | (hdr
->path_msg
<< 6) |
276 (hdr
->msg_len
& 0x3f);
277 buf
[idx
++] = (hdr
->somt
<< 7) | (hdr
->eomt
<< 6) | (hdr
->seqno
<< 4);
279 crc4
= drm_dp_msg_header_crc4(buf
, (idx
* 2) - 1);
280 buf
[idx
- 1] |= (crc4
& 0xf);
285 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr
*hdr
,
286 u8
*buf
, int buflen
, u8
*hdrlen
)
295 len
+= ((buf
[0] & 0xf0) >> 4) / 2;
298 crc4
= drm_dp_msg_header_crc4(buf
, (len
* 2) - 1);
300 if ((crc4
& 0xf) != (buf
[len
- 1] & 0xf)) {
301 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4
, buf
[len
- 1]);
305 hdr
->lct
= (buf
[0] & 0xf0) >> 4;
306 hdr
->lcr
= (buf
[0] & 0xf);
308 for (i
= 0; i
< (hdr
->lct
/ 2); i
++)
309 hdr
->rad
[i
] = buf
[idx
++];
310 hdr
->broadcast
= (buf
[idx
] >> 7) & 0x1;
311 hdr
->path_msg
= (buf
[idx
] >> 6) & 0x1;
312 hdr
->msg_len
= buf
[idx
] & 0x3f;
314 hdr
->somt
= (buf
[idx
] >> 7) & 0x1;
315 hdr
->eomt
= (buf
[idx
] >> 6) & 0x1;
316 hdr
->seqno
= (buf
[idx
] >> 4) & 0x1;
323 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body
*req
,
324 struct drm_dp_sideband_msg_tx
*raw
)
329 buf
[idx
++] = req
->req_type
& 0x7f;
331 switch (req
->req_type
) {
332 case DP_ENUM_PATH_RESOURCES
:
333 case DP_POWER_DOWN_PHY
:
334 case DP_POWER_UP_PHY
:
335 buf
[idx
] = (req
->u
.port_num
.port_number
& 0xf) << 4;
338 case DP_ALLOCATE_PAYLOAD
:
339 buf
[idx
] = (req
->u
.allocate_payload
.port_number
& 0xf) << 4 |
340 (req
->u
.allocate_payload
.number_sdp_streams
& 0xf);
342 buf
[idx
] = (req
->u
.allocate_payload
.vcpi
& 0x7f);
344 buf
[idx
] = (req
->u
.allocate_payload
.pbn
>> 8);
346 buf
[idx
] = (req
->u
.allocate_payload
.pbn
& 0xff);
348 for (i
= 0; i
< req
->u
.allocate_payload
.number_sdp_streams
/ 2; i
++) {
349 buf
[idx
] = ((req
->u
.allocate_payload
.sdp_stream_sink
[i
* 2] & 0xf) << 4) |
350 (req
->u
.allocate_payload
.sdp_stream_sink
[i
* 2 + 1] & 0xf);
353 if (req
->u
.allocate_payload
.number_sdp_streams
& 1) {
354 i
= req
->u
.allocate_payload
.number_sdp_streams
- 1;
355 buf
[idx
] = (req
->u
.allocate_payload
.sdp_stream_sink
[i
] & 0xf) << 4;
359 case DP_QUERY_PAYLOAD
:
360 buf
[idx
] = (req
->u
.query_payload
.port_number
& 0xf) << 4;
362 buf
[idx
] = (req
->u
.query_payload
.vcpi
& 0x7f);
365 case DP_REMOTE_DPCD_READ
:
366 buf
[idx
] = (req
->u
.dpcd_read
.port_number
& 0xf) << 4;
367 buf
[idx
] |= ((req
->u
.dpcd_read
.dpcd_address
& 0xf0000) >> 16) & 0xf;
369 buf
[idx
] = (req
->u
.dpcd_read
.dpcd_address
& 0xff00) >> 8;
371 buf
[idx
] = (req
->u
.dpcd_read
.dpcd_address
& 0xff);
373 buf
[idx
] = (req
->u
.dpcd_read
.num_bytes
);
377 case DP_REMOTE_DPCD_WRITE
:
378 buf
[idx
] = (req
->u
.dpcd_write
.port_number
& 0xf) << 4;
379 buf
[idx
] |= ((req
->u
.dpcd_write
.dpcd_address
& 0xf0000) >> 16) & 0xf;
381 buf
[idx
] = (req
->u
.dpcd_write
.dpcd_address
& 0xff00) >> 8;
383 buf
[idx
] = (req
->u
.dpcd_write
.dpcd_address
& 0xff);
385 buf
[idx
] = (req
->u
.dpcd_write
.num_bytes
);
387 memcpy(&buf
[idx
], req
->u
.dpcd_write
.bytes
, req
->u
.dpcd_write
.num_bytes
);
388 idx
+= req
->u
.dpcd_write
.num_bytes
;
390 case DP_REMOTE_I2C_READ
:
391 buf
[idx
] = (req
->u
.i2c_read
.port_number
& 0xf) << 4;
392 buf
[idx
] |= (req
->u
.i2c_read
.num_transactions
& 0x3);
394 for (i
= 0; i
< (req
->u
.i2c_read
.num_transactions
& 0x3); i
++) {
395 buf
[idx
] = req
->u
.i2c_read
.transactions
[i
].i2c_dev_id
& 0x7f;
397 buf
[idx
] = req
->u
.i2c_read
.transactions
[i
].num_bytes
;
399 memcpy(&buf
[idx
], req
->u
.i2c_read
.transactions
[i
].bytes
, req
->u
.i2c_read
.transactions
[i
].num_bytes
);
400 idx
+= req
->u
.i2c_read
.transactions
[i
].num_bytes
;
402 buf
[idx
] = (req
->u
.i2c_read
.transactions
[i
].no_stop_bit
& 0x1) << 4;
403 buf
[idx
] |= (req
->u
.i2c_read
.transactions
[i
].i2c_transaction_delay
& 0xf);
406 buf
[idx
] = (req
->u
.i2c_read
.read_i2c_device_id
) & 0x7f;
408 buf
[idx
] = (req
->u
.i2c_read
.num_bytes_read
);
412 case DP_REMOTE_I2C_WRITE
:
413 buf
[idx
] = (req
->u
.i2c_write
.port_number
& 0xf) << 4;
415 buf
[idx
] = (req
->u
.i2c_write
.write_i2c_device_id
) & 0x7f;
417 buf
[idx
] = (req
->u
.i2c_write
.num_bytes
);
419 memcpy(&buf
[idx
], req
->u
.i2c_write
.bytes
, req
->u
.i2c_write
.num_bytes
);
420 idx
+= req
->u
.i2c_write
.num_bytes
;
425 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req
);
427 /* Decode a sideband request we've encoded, mainly used for debugging */
429 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx
*raw
,
430 struct drm_dp_sideband_msg_req_body
*req
)
432 const u8
*buf
= raw
->msg
;
435 req
->req_type
= buf
[idx
++] & 0x7f;
436 switch (req
->req_type
) {
437 case DP_ENUM_PATH_RESOURCES
:
438 case DP_POWER_DOWN_PHY
:
439 case DP_POWER_UP_PHY
:
440 req
->u
.port_num
.port_number
= (buf
[idx
] >> 4) & 0xf;
442 case DP_ALLOCATE_PAYLOAD
:
444 struct drm_dp_allocate_payload
*a
=
445 &req
->u
.allocate_payload
;
447 a
->number_sdp_streams
= buf
[idx
] & 0xf;
448 a
->port_number
= (buf
[idx
] >> 4) & 0xf;
450 WARN_ON(buf
[++idx
] & 0x80);
451 a
->vcpi
= buf
[idx
] & 0x7f;
453 a
->pbn
= buf
[++idx
] << 8;
454 a
->pbn
|= buf
[++idx
];
457 for (i
= 0; i
< a
->number_sdp_streams
; i
++) {
458 a
->sdp_stream_sink
[i
] =
459 (buf
[idx
+ (i
/ 2)] >> ((i
% 2) ? 0 : 4)) & 0xf;
463 case DP_QUERY_PAYLOAD
:
464 req
->u
.query_payload
.port_number
= (buf
[idx
] >> 4) & 0xf;
465 WARN_ON(buf
[++idx
] & 0x80);
466 req
->u
.query_payload
.vcpi
= buf
[idx
] & 0x7f;
468 case DP_REMOTE_DPCD_READ
:
470 struct drm_dp_remote_dpcd_read
*r
= &req
->u
.dpcd_read
;
472 r
->port_number
= (buf
[idx
] >> 4) & 0xf;
474 r
->dpcd_address
= (buf
[idx
] << 16) & 0xf0000;
475 r
->dpcd_address
|= (buf
[++idx
] << 8) & 0xff00;
476 r
->dpcd_address
|= buf
[++idx
] & 0xff;
478 r
->num_bytes
= buf
[++idx
];
481 case DP_REMOTE_DPCD_WRITE
:
483 struct drm_dp_remote_dpcd_write
*w
=
486 w
->port_number
= (buf
[idx
] >> 4) & 0xf;
488 w
->dpcd_address
= (buf
[idx
] << 16) & 0xf0000;
489 w
->dpcd_address
|= (buf
[++idx
] << 8) & 0xff00;
490 w
->dpcd_address
|= buf
[++idx
] & 0xff;
492 w
->num_bytes
= buf
[++idx
];
494 w
->bytes
= kmemdup(&buf
[++idx
], w
->num_bytes
,
500 case DP_REMOTE_I2C_READ
:
502 struct drm_dp_remote_i2c_read
*r
= &req
->u
.i2c_read
;
503 struct drm_dp_remote_i2c_read_tx
*tx
;
506 r
->num_transactions
= buf
[idx
] & 0x3;
507 r
->port_number
= (buf
[idx
] >> 4) & 0xf;
508 for (i
= 0; i
< r
->num_transactions
; i
++) {
509 tx
= &r
->transactions
[i
];
511 tx
->i2c_dev_id
= buf
[++idx
] & 0x7f;
512 tx
->num_bytes
= buf
[++idx
];
513 tx
->bytes
= kmemdup(&buf
[++idx
],
520 idx
+= tx
->num_bytes
;
521 tx
->no_stop_bit
= (buf
[idx
] >> 5) & 0x1;
522 tx
->i2c_transaction_delay
= buf
[idx
] & 0xf;
526 for (i
= 0; i
< r
->num_transactions
; i
++) {
527 tx
= &r
->transactions
[i
];
533 r
->read_i2c_device_id
= buf
[++idx
] & 0x7f;
534 r
->num_bytes_read
= buf
[++idx
];
537 case DP_REMOTE_I2C_WRITE
:
539 struct drm_dp_remote_i2c_write
*w
= &req
->u
.i2c_write
;
541 w
->port_number
= (buf
[idx
] >> 4) & 0xf;
542 w
->write_i2c_device_id
= buf
[++idx
] & 0x7f;
543 w
->num_bytes
= buf
[++idx
];
544 w
->bytes
= kmemdup(&buf
[++idx
], w
->num_bytes
,
554 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req
);
557 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body
*req
,
558 int indent
, struct drm_printer
*printer
)
562 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
563 if (req
->req_type
== DP_LINK_ADDRESS
) {
564 /* No contents to print */
565 P("type=%s\n", drm_dp_mst_req_type_str(req
->req_type
));
569 P("type=%s contents:\n", drm_dp_mst_req_type_str(req
->req_type
));
572 switch (req
->req_type
) {
573 case DP_ENUM_PATH_RESOURCES
:
574 case DP_POWER_DOWN_PHY
:
575 case DP_POWER_UP_PHY
:
576 P("port=%d\n", req
->u
.port_num
.port_number
);
578 case DP_ALLOCATE_PAYLOAD
:
579 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
580 req
->u
.allocate_payload
.port_number
,
581 req
->u
.allocate_payload
.vcpi
, req
->u
.allocate_payload
.pbn
,
582 req
->u
.allocate_payload
.number_sdp_streams
,
583 req
->u
.allocate_payload
.number_sdp_streams
,
584 req
->u
.allocate_payload
.sdp_stream_sink
);
586 case DP_QUERY_PAYLOAD
:
587 P("port=%d vcpi=%d\n",
588 req
->u
.query_payload
.port_number
,
589 req
->u
.query_payload
.vcpi
);
591 case DP_REMOTE_DPCD_READ
:
592 P("port=%d dpcd_addr=%05x len=%d\n",
593 req
->u
.dpcd_read
.port_number
, req
->u
.dpcd_read
.dpcd_address
,
594 req
->u
.dpcd_read
.num_bytes
);
596 case DP_REMOTE_DPCD_WRITE
:
597 P("port=%d addr=%05x len=%d: %*ph\n",
598 req
->u
.dpcd_write
.port_number
,
599 req
->u
.dpcd_write
.dpcd_address
,
600 req
->u
.dpcd_write
.num_bytes
, req
->u
.dpcd_write
.num_bytes
,
601 req
->u
.dpcd_write
.bytes
);
603 case DP_REMOTE_I2C_READ
:
604 P("port=%d num_tx=%d id=%d size=%d:\n",
605 req
->u
.i2c_read
.port_number
,
606 req
->u
.i2c_read
.num_transactions
,
607 req
->u
.i2c_read
.read_i2c_device_id
,
608 req
->u
.i2c_read
.num_bytes_read
);
611 for (i
= 0; i
< req
->u
.i2c_read
.num_transactions
; i
++) {
612 const struct drm_dp_remote_i2c_read_tx
*rtx
=
613 &req
->u
.i2c_read
.transactions
[i
];
615 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
616 i
, rtx
->i2c_dev_id
, rtx
->num_bytes
,
617 rtx
->no_stop_bit
, rtx
->i2c_transaction_delay
,
618 rtx
->num_bytes
, rtx
->bytes
);
621 case DP_REMOTE_I2C_WRITE
:
622 P("port=%d id=%d size=%d: %*ph\n",
623 req
->u
.i2c_write
.port_number
,
624 req
->u
.i2c_write
.write_i2c_device_id
,
625 req
->u
.i2c_write
.num_bytes
, req
->u
.i2c_write
.num_bytes
,
626 req
->u
.i2c_write
.bytes
);
634 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body
);
637 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer
*p
,
638 const struct drm_dp_sideband_msg_tx
*txmsg
)
640 struct drm_dp_sideband_msg_req_body req
;
645 drm_dp_mst_rad_to_str(txmsg
->dst
->rad
, txmsg
->dst
->lct
, buf
,
647 drm_printf(p
, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
648 txmsg
->cur_offset
, txmsg
->cur_len
, txmsg
->seqno
,
649 drm_dp_mst_sideband_tx_state_str(txmsg
->state
),
650 txmsg
->path_msg
, buf
);
652 ret
= drm_dp_decode_sideband_req(txmsg
, &req
);
654 drm_printf(p
, "<failed to decode sideband req: %d>\n", ret
);
657 drm_dp_dump_sideband_msg_req_body(&req
, 1, p
);
659 switch (req
.req_type
) {
660 case DP_REMOTE_DPCD_WRITE
:
661 kfree(req
.u
.dpcd_write
.bytes
);
663 case DP_REMOTE_I2C_READ
:
664 for (i
= 0; i
< req
.u
.i2c_read
.num_transactions
; i
++)
665 kfree(req
.u
.i2c_read
.transactions
[i
].bytes
);
667 case DP_REMOTE_I2C_WRITE
:
668 kfree(req
.u
.i2c_write
.bytes
);
673 static void drm_dp_crc_sideband_chunk_req(u8
*msg
, u8 len
)
676 crc4
= drm_dp_msg_data_crc4(msg
, len
);
680 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body
*rep
,
681 struct drm_dp_sideband_msg_tx
*raw
)
686 buf
[idx
++] = (rep
->reply_type
& 0x1) << 7 | (rep
->req_type
& 0x7f);
691 static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx
*msg
,
692 struct drm_dp_sideband_msg_hdr
*hdr
,
696 * ignore out-of-order messages or messages that are part of a
699 if (!hdr
->somt
&& !msg
->have_somt
)
702 /* get length contained in this portion */
703 msg
->curchunk_idx
= 0;
704 msg
->curchunk_len
= hdr
->msg_len
;
705 msg
->curchunk_hdrlen
= hdrlen
;
707 /* we have already gotten an somt - don't bother parsing */
708 if (hdr
->somt
&& msg
->have_somt
)
712 memcpy(&msg
->initial_hdr
, hdr
,
713 sizeof(struct drm_dp_sideband_msg_hdr
));
714 msg
->have_somt
= true;
717 msg
->have_eomt
= true;
722 /* this adds a chunk of msg to the builder to get the final msg */
723 static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx
*msg
,
724 u8
*replybuf
, u8 replybuflen
)
728 memcpy(&msg
->chunk
[msg
->curchunk_idx
], replybuf
, replybuflen
);
729 msg
->curchunk_idx
+= replybuflen
;
731 if (msg
->curchunk_idx
>= msg
->curchunk_len
) {
733 crc4
= drm_dp_msg_data_crc4(msg
->chunk
, msg
->curchunk_len
- 1);
734 if (crc4
!= msg
->chunk
[msg
->curchunk_len
- 1])
735 print_hex_dump(KERN_DEBUG
, "wrong crc",
736 DUMP_PREFIX_NONE
, 16, 1,
737 msg
->chunk
, msg
->curchunk_len
, false);
738 /* copy chunk into bigger msg */
739 memcpy(&msg
->msg
[msg
->curlen
], msg
->chunk
, msg
->curchunk_len
- 1);
740 msg
->curlen
+= msg
->curchunk_len
- 1;
745 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx
*raw
,
746 struct drm_dp_sideband_msg_reply_body
*repmsg
)
750 memcpy(repmsg
->u
.link_addr
.guid
, &raw
->msg
[idx
], 16);
752 repmsg
->u
.link_addr
.nports
= raw
->msg
[idx
] & 0xf;
754 if (idx
> raw
->curlen
)
756 for (i
= 0; i
< repmsg
->u
.link_addr
.nports
; i
++) {
757 if (raw
->msg
[idx
] & 0x80)
758 repmsg
->u
.link_addr
.ports
[i
].input_port
= 1;
760 repmsg
->u
.link_addr
.ports
[i
].peer_device_type
= (raw
->msg
[idx
] >> 4) & 0x7;
761 repmsg
->u
.link_addr
.ports
[i
].port_number
= (raw
->msg
[idx
] & 0xf);
764 if (idx
> raw
->curlen
)
766 repmsg
->u
.link_addr
.ports
[i
].mcs
= (raw
->msg
[idx
] >> 7) & 0x1;
767 repmsg
->u
.link_addr
.ports
[i
].ddps
= (raw
->msg
[idx
] >> 6) & 0x1;
768 if (repmsg
->u
.link_addr
.ports
[i
].input_port
== 0)
769 repmsg
->u
.link_addr
.ports
[i
].legacy_device_plug_status
= (raw
->msg
[idx
] >> 5) & 0x1;
771 if (idx
> raw
->curlen
)
773 if (repmsg
->u
.link_addr
.ports
[i
].input_port
== 0) {
774 repmsg
->u
.link_addr
.ports
[i
].dpcd_revision
= (raw
->msg
[idx
]);
776 if (idx
> raw
->curlen
)
778 memcpy(repmsg
->u
.link_addr
.ports
[i
].peer_guid
, &raw
->msg
[idx
], 16);
780 if (idx
> raw
->curlen
)
782 repmsg
->u
.link_addr
.ports
[i
].num_sdp_streams
= (raw
->msg
[idx
] >> 4) & 0xf;
783 repmsg
->u
.link_addr
.ports
[i
].num_sdp_stream_sinks
= (raw
->msg
[idx
] & 0xf);
787 if (idx
> raw
->curlen
)
793 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx
, raw
->curlen
);
797 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx
*raw
,
798 struct drm_dp_sideband_msg_reply_body
*repmsg
)
801 repmsg
->u
.remote_dpcd_read_ack
.port_number
= raw
->msg
[idx
] & 0xf;
803 if (idx
> raw
->curlen
)
805 repmsg
->u
.remote_dpcd_read_ack
.num_bytes
= raw
->msg
[idx
];
807 if (idx
> raw
->curlen
)
810 memcpy(repmsg
->u
.remote_dpcd_read_ack
.bytes
, &raw
->msg
[idx
], repmsg
->u
.remote_dpcd_read_ack
.num_bytes
);
813 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx
, raw
->curlen
);
817 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx
*raw
,
818 struct drm_dp_sideband_msg_reply_body
*repmsg
)
821 repmsg
->u
.remote_dpcd_write_ack
.port_number
= raw
->msg
[idx
] & 0xf;
823 if (idx
> raw
->curlen
)
827 DRM_DEBUG_KMS("parse length fail %d %d\n", idx
, raw
->curlen
);
831 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx
*raw
,
832 struct drm_dp_sideband_msg_reply_body
*repmsg
)
836 repmsg
->u
.remote_i2c_read_ack
.port_number
= (raw
->msg
[idx
] & 0xf);
838 if (idx
> raw
->curlen
)
840 repmsg
->u
.remote_i2c_read_ack
.num_bytes
= raw
->msg
[idx
];
843 memcpy(repmsg
->u
.remote_i2c_read_ack
.bytes
, &raw
->msg
[idx
], repmsg
->u
.remote_i2c_read_ack
.num_bytes
);
846 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx
, raw
->curlen
);
850 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx
*raw
,
851 struct drm_dp_sideband_msg_reply_body
*repmsg
)
854 repmsg
->u
.path_resources
.port_number
= (raw
->msg
[idx
] >> 4) & 0xf;
855 repmsg
->u
.path_resources
.fec_capable
= raw
->msg
[idx
] & 0x1;
857 if (idx
> raw
->curlen
)
859 repmsg
->u
.path_resources
.full_payload_bw_number
= (raw
->msg
[idx
] << 8) | (raw
->msg
[idx
+1]);
861 if (idx
> raw
->curlen
)
863 repmsg
->u
.path_resources
.avail_payload_bw_number
= (raw
->msg
[idx
] << 8) | (raw
->msg
[idx
+1]);
865 if (idx
> raw
->curlen
)
869 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx
, raw
->curlen
);
873 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx
*raw
,
874 struct drm_dp_sideband_msg_reply_body
*repmsg
)
877 repmsg
->u
.allocate_payload
.port_number
= (raw
->msg
[idx
] >> 4) & 0xf;
879 if (idx
> raw
->curlen
)
881 repmsg
->u
.allocate_payload
.vcpi
= raw
->msg
[idx
];
883 if (idx
> raw
->curlen
)
885 repmsg
->u
.allocate_payload
.allocated_pbn
= (raw
->msg
[idx
] << 8) | (raw
->msg
[idx
+1]);
887 if (idx
> raw
->curlen
)
891 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx
, raw
->curlen
);
895 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx
*raw
,
896 struct drm_dp_sideband_msg_reply_body
*repmsg
)
899 repmsg
->u
.query_payload
.port_number
= (raw
->msg
[idx
] >> 4) & 0xf;
901 if (idx
> raw
->curlen
)
903 repmsg
->u
.query_payload
.allocated_pbn
= (raw
->msg
[idx
] << 8) | (raw
->msg
[idx
+ 1]);
905 if (idx
> raw
->curlen
)
909 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx
, raw
->curlen
);
913 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx
*raw
,
914 struct drm_dp_sideband_msg_reply_body
*repmsg
)
918 repmsg
->u
.port_number
.port_number
= (raw
->msg
[idx
] >> 4) & 0xf;
920 if (idx
> raw
->curlen
) {
921 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
928 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx
*raw
,
929 struct drm_dp_sideband_msg_reply_body
*msg
)
931 memset(msg
, 0, sizeof(*msg
));
932 msg
->reply_type
= (raw
->msg
[0] & 0x80) >> 7;
933 msg
->req_type
= (raw
->msg
[0] & 0x7f);
935 if (msg
->reply_type
== DP_SIDEBAND_REPLY_NAK
) {
936 memcpy(msg
->u
.nak
.guid
, &raw
->msg
[1], 16);
937 msg
->u
.nak
.reason
= raw
->msg
[17];
938 msg
->u
.nak
.nak_data
= raw
->msg
[18];
942 switch (msg
->req_type
) {
943 case DP_LINK_ADDRESS
:
944 return drm_dp_sideband_parse_link_address(raw
, msg
);
945 case DP_QUERY_PAYLOAD
:
946 return drm_dp_sideband_parse_query_payload_ack(raw
, msg
);
947 case DP_REMOTE_DPCD_READ
:
948 return drm_dp_sideband_parse_remote_dpcd_read(raw
, msg
);
949 case DP_REMOTE_DPCD_WRITE
:
950 return drm_dp_sideband_parse_remote_dpcd_write(raw
, msg
);
951 case DP_REMOTE_I2C_READ
:
952 return drm_dp_sideband_parse_remote_i2c_read_ack(raw
, msg
);
953 case DP_ENUM_PATH_RESOURCES
:
954 return drm_dp_sideband_parse_enum_path_resources_ack(raw
, msg
);
955 case DP_ALLOCATE_PAYLOAD
:
956 return drm_dp_sideband_parse_allocate_payload_ack(raw
, msg
);
957 case DP_POWER_DOWN_PHY
:
958 case DP_POWER_UP_PHY
:
959 return drm_dp_sideband_parse_power_updown_phy_ack(raw
, msg
);
960 case DP_CLEAR_PAYLOAD_ID_TABLE
:
961 return true; /* since there's nothing to parse */
963 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg
->req_type
,
964 drm_dp_mst_req_type_str(msg
->req_type
));
969 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx
*raw
,
970 struct drm_dp_sideband_msg_req_body
*msg
)
974 msg
->u
.conn_stat
.port_number
= (raw
->msg
[idx
] & 0xf0) >> 4;
976 if (idx
> raw
->curlen
)
979 memcpy(msg
->u
.conn_stat
.guid
, &raw
->msg
[idx
], 16);
981 if (idx
> raw
->curlen
)
984 msg
->u
.conn_stat
.legacy_device_plug_status
= (raw
->msg
[idx
] >> 6) & 0x1;
985 msg
->u
.conn_stat
.displayport_device_plug_status
= (raw
->msg
[idx
] >> 5) & 0x1;
986 msg
->u
.conn_stat
.message_capability_status
= (raw
->msg
[idx
] >> 4) & 0x1;
987 msg
->u
.conn_stat
.input_port
= (raw
->msg
[idx
] >> 3) & 0x1;
988 msg
->u
.conn_stat
.peer_device_type
= (raw
->msg
[idx
] & 0x7);
992 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx
, raw
->curlen
);
996 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx
*raw
,
997 struct drm_dp_sideband_msg_req_body
*msg
)
1001 msg
->u
.resource_stat
.port_number
= (raw
->msg
[idx
] & 0xf0) >> 4;
1003 if (idx
> raw
->curlen
)
1006 memcpy(msg
->u
.resource_stat
.guid
, &raw
->msg
[idx
], 16);
1008 if (idx
> raw
->curlen
)
1011 msg
->u
.resource_stat
.available_pbn
= (raw
->msg
[idx
] << 8) | (raw
->msg
[idx
+ 1]);
1015 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx
, raw
->curlen
);
1019 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx
*raw
,
1020 struct drm_dp_sideband_msg_req_body
*msg
)
1022 memset(msg
, 0, sizeof(*msg
));
1023 msg
->req_type
= (raw
->msg
[0] & 0x7f);
1025 switch (msg
->req_type
) {
1026 case DP_CONNECTION_STATUS_NOTIFY
:
1027 return drm_dp_sideband_parse_connection_status_notify(raw
, msg
);
1028 case DP_RESOURCE_STATUS_NOTIFY
:
1029 return drm_dp_sideband_parse_resource_status_notify(raw
, msg
);
1031 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg
->req_type
,
1032 drm_dp_mst_req_type_str(msg
->req_type
));
1037 static void build_dpcd_write(struct drm_dp_sideband_msg_tx
*msg
,
1038 u8 port_num
, u32 offset
, u8 num_bytes
, u8
*bytes
)
1040 struct drm_dp_sideband_msg_req_body req
;
1042 req
.req_type
= DP_REMOTE_DPCD_WRITE
;
1043 req
.u
.dpcd_write
.port_number
= port_num
;
1044 req
.u
.dpcd_write
.dpcd_address
= offset
;
1045 req
.u
.dpcd_write
.num_bytes
= num_bytes
;
1046 req
.u
.dpcd_write
.bytes
= bytes
;
1047 drm_dp_encode_sideband_req(&req
, msg
);
1050 static void build_link_address(struct drm_dp_sideband_msg_tx
*msg
)
1052 struct drm_dp_sideband_msg_req_body req
;
1054 req
.req_type
= DP_LINK_ADDRESS
;
1055 drm_dp_encode_sideband_req(&req
, msg
);
1058 static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx
*msg
)
1060 struct drm_dp_sideband_msg_req_body req
;
1062 req
.req_type
= DP_CLEAR_PAYLOAD_ID_TABLE
;
1063 drm_dp_encode_sideband_req(&req
, msg
);
1066 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx
*msg
,
1069 struct drm_dp_sideband_msg_req_body req
;
1071 req
.req_type
= DP_ENUM_PATH_RESOURCES
;
1072 req
.u
.port_num
.port_number
= port_num
;
1073 drm_dp_encode_sideband_req(&req
, msg
);
1074 msg
->path_msg
= true;
1078 static void build_allocate_payload(struct drm_dp_sideband_msg_tx
*msg
,
1080 u8 vcpi
, uint16_t pbn
,
1081 u8 number_sdp_streams
,
1082 u8
*sdp_stream_sink
)
1084 struct drm_dp_sideband_msg_req_body req
;
1085 memset(&req
, 0, sizeof(req
));
1086 req
.req_type
= DP_ALLOCATE_PAYLOAD
;
1087 req
.u
.allocate_payload
.port_number
= port_num
;
1088 req
.u
.allocate_payload
.vcpi
= vcpi
;
1089 req
.u
.allocate_payload
.pbn
= pbn
;
1090 req
.u
.allocate_payload
.number_sdp_streams
= number_sdp_streams
;
1091 memcpy(req
.u
.allocate_payload
.sdp_stream_sink
, sdp_stream_sink
,
1092 number_sdp_streams
);
1093 drm_dp_encode_sideband_req(&req
, msg
);
1094 msg
->path_msg
= true;
1097 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx
*msg
,
1098 int port_num
, bool power_up
)
1100 struct drm_dp_sideband_msg_req_body req
;
1103 req
.req_type
= DP_POWER_UP_PHY
;
1105 req
.req_type
= DP_POWER_DOWN_PHY
;
1107 req
.u
.port_num
.port_number
= port_num
;
1108 drm_dp_encode_sideband_req(&req
, msg
);
1109 msg
->path_msg
= true;
1112 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr
*mgr
,
1113 struct drm_dp_vcpi
*vcpi
)
1117 mutex_lock(&mgr
->payload_lock
);
1118 ret
= find_first_zero_bit(&mgr
->payload_mask
, mgr
->max_payloads
+ 1);
1119 if (ret
> mgr
->max_payloads
) {
1121 DRM_DEBUG_KMS("out of payload ids %d\n", ret
);
1125 vcpi_ret
= find_first_zero_bit(&mgr
->vcpi_mask
, mgr
->max_payloads
+ 1);
1126 if (vcpi_ret
> mgr
->max_payloads
) {
1128 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret
);
1132 set_bit(ret
, &mgr
->payload_mask
);
1133 set_bit(vcpi_ret
, &mgr
->vcpi_mask
);
1134 vcpi
->vcpi
= vcpi_ret
+ 1;
1135 mgr
->proposed_vcpis
[ret
- 1] = vcpi
;
1137 mutex_unlock(&mgr
->payload_lock
);
1141 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr
*mgr
,
1148 mutex_lock(&mgr
->payload_lock
);
1149 DRM_DEBUG_KMS("putting payload %d\n", vcpi
);
1150 clear_bit(vcpi
- 1, &mgr
->vcpi_mask
);
1152 for (i
= 0; i
< mgr
->max_payloads
; i
++) {
1153 if (mgr
->proposed_vcpis
[i
] &&
1154 mgr
->proposed_vcpis
[i
]->vcpi
== vcpi
) {
1155 mgr
->proposed_vcpis
[i
] = NULL
;
1156 clear_bit(i
+ 1, &mgr
->payload_mask
);
1159 mutex_unlock(&mgr
->payload_lock
);
1162 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr
*mgr
,
1163 struct drm_dp_sideband_msg_tx
*txmsg
)
1168 * All updates to txmsg->state are protected by mgr->qlock, and the two
1169 * cases we check here are terminal states. For those the barriers
1170 * provided by the wake_up/wait_event pair are enough.
1172 state
= READ_ONCE(txmsg
->state
);
1173 return (state
== DRM_DP_SIDEBAND_TX_RX
||
1174 state
== DRM_DP_SIDEBAND_TX_TIMEOUT
);
1177 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch
*mstb
,
1178 struct drm_dp_sideband_msg_tx
*txmsg
)
1180 struct drm_dp_mst_topology_mgr
*mgr
= mstb
->mgr
;
1183 ret
= wait_event_timeout(mgr
->tx_waitq
,
1184 check_txmsg_state(mgr
, txmsg
),
1186 mutex_lock(&mstb
->mgr
->qlock
);
1188 if (txmsg
->state
== DRM_DP_SIDEBAND_TX_TIMEOUT
) {
1193 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg
, txmsg
->state
, txmsg
->seqno
);
1195 /* dump some state */
1199 if (txmsg
->state
== DRM_DP_SIDEBAND_TX_QUEUED
||
1200 txmsg
->state
== DRM_DP_SIDEBAND_TX_START_SEND
)
1201 list_del(&txmsg
->next
);
1204 if (unlikely(ret
== -EIO
) && drm_debug_enabled(DRM_UT_DP
)) {
1205 struct drm_printer p
= drm_debug_printer(DBG_PREFIX
);
1207 drm_dp_mst_dump_sideband_msg_tx(&p
, txmsg
);
1209 mutex_unlock(&mgr
->qlock
);
1211 drm_dp_mst_kick_tx(mgr
);
1215 static struct drm_dp_mst_branch
*drm_dp_add_mst_branch_device(u8 lct
, u8
*rad
)
1217 struct drm_dp_mst_branch
*mstb
;
1219 mstb
= kzalloc(sizeof(*mstb
), GFP_KERNEL
);
1225 memcpy(mstb
->rad
, rad
, lct
/ 2);
1226 INIT_LIST_HEAD(&mstb
->ports
);
1227 kref_init(&mstb
->topology_kref
);
1228 kref_init(&mstb
->malloc_kref
);
1232 static void drm_dp_free_mst_branch_device(struct kref
*kref
)
1234 struct drm_dp_mst_branch
*mstb
=
1235 container_of(kref
, struct drm_dp_mst_branch
, malloc_kref
);
1237 if (mstb
->port_parent
)
1238 drm_dp_mst_put_port_malloc(mstb
->port_parent
);
1244 * DOC: Branch device and port refcounting
1246 * Topology refcount overview
1247 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1249 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1250 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1251 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1253 * Topology refcounts are not exposed to drivers, and are handled internally
1254 * by the DP MST helpers. The helpers use them in order to prevent the
1255 * in-memory topology state from being changed in the middle of critical
1256 * operations like changing the internal state of payload allocations. This
1257 * means each branch and port will be considered to be connected to the rest
1258 * of the topology until its topology refcount reaches zero. Additionally,
1259 * for ports this means that their associated &struct drm_connector will stay
1260 * registered with userspace until the port's refcount reaches 0.
1262 * Malloc refcount overview
1263 * ~~~~~~~~~~~~~~~~~~~~~~~~
1265 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1266 * drm_dp_mst_branch allocated even after all of its topology references have
1267 * been dropped, so that the driver or MST helpers can safely access each
1268 * branch's last known state before it was disconnected from the topology.
1269 * When the malloc refcount of a port or branch reaches 0, the memory
1270 * allocation containing the &struct drm_dp_mst_branch or &struct
1271 * drm_dp_mst_port respectively will be freed.
1273 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1274 * to drivers. As of writing this documentation, there are no drivers that
1275 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1276 * helpers. Exposing this API to drivers in a race-free manner would take more
1277 * tweaking of the refcounting scheme, however patches are welcome provided
1278 * there is a legitimate driver usecase for this.
1280 * Refcount relationships in a topology
1281 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1283 * Let's take a look at why the relationship between topology and malloc
1284 * refcounts is designed the way it is.
1286 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1288 * An example of topology and malloc refs in a DP MST topology with two
1289 * active payloads. Topology refcount increments are indicated by solid
1290 * lines, and malloc refcount increments are indicated by dashed lines.
1291 * Each starts from the branch which incremented the refcount, and ends at
1292 * the branch to which the refcount belongs to, i.e. the arrow points the
1293 * same way as the C pointers used to reference a structure.
1295 * As you can see in the above figure, every branch increments the topology
1296 * refcount of its children, and increments the malloc refcount of its
1297 * parent. Additionally, every payload increments the malloc refcount of its
1298 * assigned port by 1.
1300 * So, what would happen if MSTB #3 from the above figure was unplugged from
1301 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1302 * topology would start to look like the figure below.
1304 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1306 * Ports and branch devices which have been released from memory are
1307 * colored grey, and references which have been removed are colored red.
1309 * Whenever a port or branch device's topology refcount reaches zero, it will
1310 * decrement the topology refcounts of all its children, the malloc refcount
1311 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1312 * #4, this means they both have been disconnected from the topology and freed
1313 * from memory. But, because payload #2 is still holding a reference to port
1314 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1315 * is still accessible from memory. This also means port #3 has not yet
1316 * decremented the malloc refcount of MSTB #3, so its &struct
1317 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1318 * malloc refcount reaches 0.
1320 * This relationship is necessary because in order to release payload #2, we
1321 * need to be able to figure out the last relative of port #3 that's still
1322 * connected to the topology. In this case, we would travel up the topology as
1325 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1327 * And finally, remove payload #2 by communicating with port #2 through
1328 * sideband transactions.
1332 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1334 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1336 * Increments &drm_dp_mst_branch.malloc_kref. When
1337 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1338 * will be released and @mstb may no longer be used.
1340 * See also: drm_dp_mst_put_mstb_malloc()
1343 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch
*mstb
)
1345 kref_get(&mstb
->malloc_kref
);
1346 DRM_DEBUG("mstb %p (%d)\n", mstb
, kref_read(&mstb
->malloc_kref
));
1350 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1352 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1354 * Decrements &drm_dp_mst_branch.malloc_kref. When
1355 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1356 * will be released and @mstb may no longer be used.
1358 * See also: drm_dp_mst_get_mstb_malloc()
1361 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch
*mstb
)
1363 DRM_DEBUG("mstb %p (%d)\n", mstb
, kref_read(&mstb
->malloc_kref
) - 1);
1364 kref_put(&mstb
->malloc_kref
, drm_dp_free_mst_branch_device
);
1367 static void drm_dp_free_mst_port(struct kref
*kref
)
1369 struct drm_dp_mst_port
*port
=
1370 container_of(kref
, struct drm_dp_mst_port
, malloc_kref
);
1372 drm_dp_mst_put_mstb_malloc(port
->parent
);
1377 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1378 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1380 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1381 * reaches 0, the memory allocation for @port will be released and @port may
1382 * no longer be used.
1384 * Because @port could potentially be freed at any time by the DP MST helpers
1385 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1386 * function, drivers that which to make use of &struct drm_dp_mst_port should
1387 * ensure that they grab at least one main malloc reference to their MST ports
1388 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1389 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1391 * See also: drm_dp_mst_put_port_malloc()
1394 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port
*port
)
1396 kref_get(&port
->malloc_kref
);
1397 DRM_DEBUG("port %p (%d)\n", port
, kref_read(&port
->malloc_kref
));
1399 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc
);
1402 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1403 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1405 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1406 * reaches 0, the memory allocation for @port will be released and @port may
1407 * no longer be used.
1409 * See also: drm_dp_mst_get_port_malloc()
1412 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port
*port
)
1414 DRM_DEBUG("port %p (%d)\n", port
, kref_read(&port
->malloc_kref
) - 1);
1415 kref_put(&port
->malloc_kref
, drm_dp_free_mst_port
);
1417 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc
);
1419 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1421 #define STACK_DEPTH 8
1423 static noinline
void
1424 __topology_ref_save(struct drm_dp_mst_topology_mgr
*mgr
,
1425 struct drm_dp_mst_topology_ref_history
*history
,
1426 enum drm_dp_mst_topology_ref_type type
)
1428 struct drm_dp_mst_topology_ref_entry
*entry
= NULL
;
1429 depot_stack_handle_t backtrace
;
1430 ulong stack_entries
[STACK_DEPTH
];
1434 n
= stack_trace_save(stack_entries
, ARRAY_SIZE(stack_entries
), 1);
1435 backtrace
= stack_depot_save(stack_entries
, n
, GFP_KERNEL
);
1439 /* Try to find an existing entry for this backtrace */
1440 for (i
= 0; i
< history
->len
; i
++) {
1441 if (history
->entries
[i
].backtrace
== backtrace
) {
1442 entry
= &history
->entries
[i
];
1447 /* Otherwise add one */
1449 struct drm_dp_mst_topology_ref_entry
*new;
1450 int new_len
= history
->len
+ 1;
1452 new = krealloc(history
->entries
, sizeof(*new) * new_len
,
1457 entry
= &new[history
->len
];
1458 history
->len
= new_len
;
1459 history
->entries
= new;
1461 entry
->backtrace
= backtrace
;
1466 entry
->ts_nsec
= ktime_get_ns();
1470 topology_ref_history_cmp(const void *a
, const void *b
)
1472 const struct drm_dp_mst_topology_ref_entry
*entry_a
= a
, *entry_b
= b
;
1474 if (entry_a
->ts_nsec
> entry_b
->ts_nsec
)
1476 else if (entry_a
->ts_nsec
< entry_b
->ts_nsec
)
1482 static inline const char *
1483 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type
)
1485 if (type
== DRM_DP_MST_TOPOLOGY_REF_GET
)
1492 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history
*history
,
1493 void *ptr
, const char *type_str
)
1495 struct drm_printer p
= drm_debug_printer(DBG_PREFIX
);
1496 char *buf
= kzalloc(PAGE_SIZE
, GFP_KERNEL
);
1505 /* First, sort the list so that it goes from oldest to newest
1508 sort(history
->entries
, history
->len
, sizeof(*history
->entries
),
1509 topology_ref_history_cmp
, NULL
);
1511 drm_printf(&p
, "%s (%p) topology count reached 0, dumping history:\n",
1514 for (i
= 0; i
< history
->len
; i
++) {
1515 const struct drm_dp_mst_topology_ref_entry
*entry
=
1516 &history
->entries
[i
];
1519 u64 ts_nsec
= entry
->ts_nsec
;
1520 u32 rem_nsec
= do_div(ts_nsec
, 1000000000);
1522 nr_entries
= stack_depot_fetch(entry
->backtrace
, &entries
);
1523 stack_trace_snprint(buf
, PAGE_SIZE
, entries
, nr_entries
, 4);
1525 drm_printf(&p
, " %d %ss (last at %5llu.%06u):\n%s",
1527 topology_ref_type_to_str(entry
->type
),
1528 ts_nsec
, rem_nsec
/ 1000, buf
);
1531 /* Now free the history, since this is the only time we expose it */
1532 kfree(history
->entries
);
1537 static __always_inline
void
1538 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch
*mstb
)
1540 __dump_topology_ref_history(&mstb
->topology_ref_history
, mstb
,
1544 static __always_inline
void
1545 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port
*port
)
1547 __dump_topology_ref_history(&port
->topology_ref_history
, port
,
1551 static __always_inline
void
1552 save_mstb_topology_ref(struct drm_dp_mst_branch
*mstb
,
1553 enum drm_dp_mst_topology_ref_type type
)
1555 __topology_ref_save(mstb
->mgr
, &mstb
->topology_ref_history
, type
);
1558 static __always_inline
void
1559 save_port_topology_ref(struct drm_dp_mst_port
*port
,
1560 enum drm_dp_mst_topology_ref_type type
)
1562 __topology_ref_save(port
->mgr
, &port
->topology_ref_history
, type
);
1566 topology_ref_history_lock(struct drm_dp_mst_topology_mgr
*mgr
)
1568 mutex_lock(&mgr
->topology_ref_history_lock
);
1572 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr
*mgr
)
1574 mutex_unlock(&mgr
->topology_ref_history_lock
);
1578 topology_ref_history_lock(struct drm_dp_mst_topology_mgr
*mgr
) {}
1580 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr
*mgr
) {}
1582 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch
*mstb
) {}
1584 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port
*port
) {}
1585 #define save_mstb_topology_ref(mstb, type)
1586 #define save_port_topology_ref(port, type)
1589 static void drm_dp_destroy_mst_branch_device(struct kref
*kref
)
1591 struct drm_dp_mst_branch
*mstb
=
1592 container_of(kref
, struct drm_dp_mst_branch
, topology_kref
);
1593 struct drm_dp_mst_topology_mgr
*mgr
= mstb
->mgr
;
1595 drm_dp_mst_dump_mstb_topology_history(mstb
);
1597 INIT_LIST_HEAD(&mstb
->destroy_next
);
1600 * This can get called under mgr->mutex, so we need to perform the
1601 * actual destruction of the mstb in another worker
1603 mutex_lock(&mgr
->delayed_destroy_lock
);
1604 list_add(&mstb
->destroy_next
, &mgr
->destroy_branch_device_list
);
1605 mutex_unlock(&mgr
->delayed_destroy_lock
);
1606 schedule_work(&mgr
->delayed_destroy_work
);
1610 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1611 * branch device unless it's zero
1612 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1614 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1615 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1616 * reached 0). Holding a topology reference implies that a malloc reference
1617 * will be held to @mstb as long as the user holds the topology reference.
1619 * Care should be taken to ensure that the user has at least one malloc
1620 * reference to @mstb. If you already have a topology reference to @mstb, you
1621 * should use drm_dp_mst_topology_get_mstb() instead.
1624 * drm_dp_mst_topology_get_mstb()
1625 * drm_dp_mst_topology_put_mstb()
1628 * * 1: A topology reference was grabbed successfully
1629 * * 0: @port is no longer in the topology, no reference was grabbed
1631 static int __must_check
1632 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch
*mstb
)
1636 topology_ref_history_lock(mstb
->mgr
);
1637 ret
= kref_get_unless_zero(&mstb
->topology_kref
);
1639 DRM_DEBUG("mstb %p (%d)\n",
1640 mstb
, kref_read(&mstb
->topology_kref
));
1641 save_mstb_topology_ref(mstb
, DRM_DP_MST_TOPOLOGY_REF_GET
);
1644 topology_ref_history_unlock(mstb
->mgr
);
1650 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1652 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1654 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1655 * not it's already reached 0. This is only valid to use in scenarios where
1656 * you are already guaranteed to have at least one active topology reference
1657 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1660 * drm_dp_mst_topology_try_get_mstb()
1661 * drm_dp_mst_topology_put_mstb()
1663 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch
*mstb
)
1665 topology_ref_history_lock(mstb
->mgr
);
1667 save_mstb_topology_ref(mstb
, DRM_DP_MST_TOPOLOGY_REF_GET
);
1668 WARN_ON(kref_read(&mstb
->topology_kref
) == 0);
1669 kref_get(&mstb
->topology_kref
);
1670 DRM_DEBUG("mstb %p (%d)\n", mstb
, kref_read(&mstb
->topology_kref
));
1672 topology_ref_history_unlock(mstb
->mgr
);
1676 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1678 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1680 * Releases a topology reference from @mstb by decrementing
1681 * &drm_dp_mst_branch.topology_kref.
1684 * drm_dp_mst_topology_try_get_mstb()
1685 * drm_dp_mst_topology_get_mstb()
1688 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch
*mstb
)
1690 topology_ref_history_lock(mstb
->mgr
);
1692 DRM_DEBUG("mstb %p (%d)\n",
1693 mstb
, kref_read(&mstb
->topology_kref
) - 1);
1694 save_mstb_topology_ref(mstb
, DRM_DP_MST_TOPOLOGY_REF_PUT
);
1696 topology_ref_history_unlock(mstb
->mgr
);
1697 kref_put(&mstb
->topology_kref
, drm_dp_destroy_mst_branch_device
);
1700 static void drm_dp_destroy_port(struct kref
*kref
)
1702 struct drm_dp_mst_port
*port
=
1703 container_of(kref
, struct drm_dp_mst_port
, topology_kref
);
1704 struct drm_dp_mst_topology_mgr
*mgr
= port
->mgr
;
1706 drm_dp_mst_dump_port_topology_history(port
);
1708 /* There's nothing that needs locking to destroy an input port yet */
1710 drm_dp_mst_put_port_malloc(port
);
1714 kfree(port
->cached_edid
);
1717 * we can't destroy the connector here, as we might be holding the
1718 * mode_config.mutex from an EDID retrieval
1720 mutex_lock(&mgr
->delayed_destroy_lock
);
1721 list_add(&port
->next
, &mgr
->destroy_port_list
);
1722 mutex_unlock(&mgr
->delayed_destroy_lock
);
1723 schedule_work(&mgr
->delayed_destroy_work
);
1727 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1728 * port unless it's zero
1729 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1731 * Attempts to grab a topology reference to @port, if it hasn't yet been
1732 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1733 * 0). Holding a topology reference implies that a malloc reference will be
1734 * held to @port as long as the user holds the topology reference.
1736 * Care should be taken to ensure that the user has at least one malloc
1737 * reference to @port. If you already have a topology reference to @port, you
1738 * should use drm_dp_mst_topology_get_port() instead.
1741 * drm_dp_mst_topology_get_port()
1742 * drm_dp_mst_topology_put_port()
1745 * * 1: A topology reference was grabbed successfully
1746 * * 0: @port is no longer in the topology, no reference was grabbed
1748 static int __must_check
1749 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port
*port
)
1753 topology_ref_history_lock(port
->mgr
);
1754 ret
= kref_get_unless_zero(&port
->topology_kref
);
1756 DRM_DEBUG("port %p (%d)\n",
1757 port
, kref_read(&port
->topology_kref
));
1758 save_port_topology_ref(port
, DRM_DP_MST_TOPOLOGY_REF_GET
);
1761 topology_ref_history_unlock(port
->mgr
);
1766 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1767 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1769 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1770 * not it's already reached 0. This is only valid to use in scenarios where
1771 * you are already guaranteed to have at least one active topology reference
1772 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1775 * drm_dp_mst_topology_try_get_port()
1776 * drm_dp_mst_topology_put_port()
1778 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port
*port
)
1780 topology_ref_history_lock(port
->mgr
);
1782 WARN_ON(kref_read(&port
->topology_kref
) == 0);
1783 kref_get(&port
->topology_kref
);
1784 DRM_DEBUG("port %p (%d)\n", port
, kref_read(&port
->topology_kref
));
1785 save_port_topology_ref(port
, DRM_DP_MST_TOPOLOGY_REF_GET
);
1787 topology_ref_history_unlock(port
->mgr
);
1791 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1792 * @port: The &struct drm_dp_mst_port to release the topology reference from
1794 * Releases a topology reference from @port by decrementing
1795 * &drm_dp_mst_port.topology_kref.
1798 * drm_dp_mst_topology_try_get_port()
1799 * drm_dp_mst_topology_get_port()
1801 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port
*port
)
1803 topology_ref_history_lock(port
->mgr
);
1805 DRM_DEBUG("port %p (%d)\n",
1806 port
, kref_read(&port
->topology_kref
) - 1);
1807 save_port_topology_ref(port
, DRM_DP_MST_TOPOLOGY_REF_PUT
);
1809 topology_ref_history_unlock(port
->mgr
);
1810 kref_put(&port
->topology_kref
, drm_dp_destroy_port
);
1813 static struct drm_dp_mst_branch
*
1814 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch
*mstb
,
1815 struct drm_dp_mst_branch
*to_find
)
1817 struct drm_dp_mst_port
*port
;
1818 struct drm_dp_mst_branch
*rmstb
;
1820 if (to_find
== mstb
)
1823 list_for_each_entry(port
, &mstb
->ports
, next
) {
1825 rmstb
= drm_dp_mst_topology_get_mstb_validated_locked(
1826 port
->mstb
, to_find
);
1834 static struct drm_dp_mst_branch
*
1835 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr
*mgr
,
1836 struct drm_dp_mst_branch
*mstb
)
1838 struct drm_dp_mst_branch
*rmstb
= NULL
;
1840 mutex_lock(&mgr
->lock
);
1841 if (mgr
->mst_primary
) {
1842 rmstb
= drm_dp_mst_topology_get_mstb_validated_locked(
1843 mgr
->mst_primary
, mstb
);
1845 if (rmstb
&& !drm_dp_mst_topology_try_get_mstb(rmstb
))
1848 mutex_unlock(&mgr
->lock
);
1852 static struct drm_dp_mst_port
*
1853 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch
*mstb
,
1854 struct drm_dp_mst_port
*to_find
)
1856 struct drm_dp_mst_port
*port
, *mport
;
1858 list_for_each_entry(port
, &mstb
->ports
, next
) {
1859 if (port
== to_find
)
1863 mport
= drm_dp_mst_topology_get_port_validated_locked(
1864 port
->mstb
, to_find
);
1872 static struct drm_dp_mst_port
*
1873 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr
*mgr
,
1874 struct drm_dp_mst_port
*port
)
1876 struct drm_dp_mst_port
*rport
= NULL
;
1878 mutex_lock(&mgr
->lock
);
1879 if (mgr
->mst_primary
) {
1880 rport
= drm_dp_mst_topology_get_port_validated_locked(
1881 mgr
->mst_primary
, port
);
1883 if (rport
&& !drm_dp_mst_topology_try_get_port(rport
))
1886 mutex_unlock(&mgr
->lock
);
1890 static struct drm_dp_mst_port
*drm_dp_get_port(struct drm_dp_mst_branch
*mstb
, u8 port_num
)
1892 struct drm_dp_mst_port
*port
;
1895 list_for_each_entry(port
, &mstb
->ports
, next
) {
1896 if (port
->port_num
== port_num
) {
1897 ret
= drm_dp_mst_topology_try_get_port(port
);
1898 return ret
? port
: NULL
;
1906 * calculate a new RAD for this MST branch device
1907 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1908 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1910 static u8
drm_dp_calculate_rad(struct drm_dp_mst_port
*port
,
1913 int parent_lct
= port
->parent
->lct
;
1915 int idx
= (parent_lct
- 1) / 2;
1916 if (parent_lct
> 1) {
1917 memcpy(rad
, port
->parent
->rad
, idx
+ 1);
1918 shift
= (parent_lct
% 2) ? 4 : 0;
1922 rad
[idx
] |= port
->port_num
<< shift
;
1923 return parent_lct
+ 1;
1926 static bool drm_dp_mst_is_end_device(u8 pdt
, bool mcs
)
1929 case DP_PEER_DEVICE_DP_LEGACY_CONV
:
1930 case DP_PEER_DEVICE_SST_SINK
:
1932 case DP_PEER_DEVICE_MST_BRANCHING
:
1933 /* For sst branch device */
1943 drm_dp_port_set_pdt(struct drm_dp_mst_port
*port
, u8 new_pdt
,
1946 struct drm_dp_mst_topology_mgr
*mgr
= port
->mgr
;
1947 struct drm_dp_mst_branch
*mstb
;
1951 if (port
->pdt
== new_pdt
&& port
->mcs
== new_mcs
)
1954 /* Teardown the old pdt, if there is one */
1955 if (port
->pdt
!= DP_PEER_DEVICE_NONE
) {
1956 if (drm_dp_mst_is_end_device(port
->pdt
, port
->mcs
)) {
1958 * If the new PDT would also have an i2c bus,
1959 * don't bother with reregistering it
1961 if (new_pdt
!= DP_PEER_DEVICE_NONE
&&
1962 drm_dp_mst_is_end_device(new_pdt
, new_mcs
)) {
1963 port
->pdt
= new_pdt
;
1964 port
->mcs
= new_mcs
;
1968 /* remove i2c over sideband */
1969 drm_dp_mst_unregister_i2c_bus(&port
->aux
);
1971 mutex_lock(&mgr
->lock
);
1972 drm_dp_mst_topology_put_mstb(port
->mstb
);
1974 mutex_unlock(&mgr
->lock
);
1978 port
->pdt
= new_pdt
;
1979 port
->mcs
= new_mcs
;
1981 if (port
->pdt
!= DP_PEER_DEVICE_NONE
) {
1982 if (drm_dp_mst_is_end_device(port
->pdt
, port
->mcs
)) {
1983 /* add i2c over sideband */
1984 ret
= drm_dp_mst_register_i2c_bus(&port
->aux
);
1986 lct
= drm_dp_calculate_rad(port
, rad
);
1987 mstb
= drm_dp_add_mst_branch_device(lct
, rad
);
1990 DRM_ERROR("Failed to create MSTB for port %p",
1995 mutex_lock(&mgr
->lock
);
1997 mstb
->mgr
= port
->mgr
;
1998 mstb
->port_parent
= port
;
2001 * Make sure this port's memory allocation stays
2002 * around until its child MSTB releases it
2004 drm_dp_mst_get_port_malloc(port
);
2005 mutex_unlock(&mgr
->lock
);
2007 /* And make sure we send a link address for this */
2014 port
->pdt
= DP_PEER_DEVICE_NONE
;
2019 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2020 * @aux: Fake sideband AUX CH
2021 * @offset: address of the (first) register to read
2022 * @buffer: buffer to store the register values
2023 * @size: number of bytes in @buffer
2025 * Performs the same functionality for remote devices via
2026 * sideband messaging as drm_dp_dpcd_read() does for local
2027 * devices via actual AUX CH.
2029 * Return: Number of bytes read, or negative error code on failure.
2031 ssize_t
drm_dp_mst_dpcd_read(struct drm_dp_aux
*aux
,
2032 unsigned int offset
, void *buffer
, size_t size
)
2034 struct drm_dp_mst_port
*port
= container_of(aux
, struct drm_dp_mst_port
,
2037 return drm_dp_send_dpcd_read(port
->mgr
, port
,
2038 offset
, size
, buffer
);
2042 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2043 * @aux: Fake sideband AUX CH
2044 * @offset: address of the (first) register to write
2045 * @buffer: buffer containing the values to write
2046 * @size: number of bytes in @buffer
2048 * Performs the same functionality for remote devices via
2049 * sideband messaging as drm_dp_dpcd_write() does for local
2050 * devices via actual AUX CH.
2052 * Return: number of bytes written on success, negative error code on failure.
2054 ssize_t
drm_dp_mst_dpcd_write(struct drm_dp_aux
*aux
,
2055 unsigned int offset
, void *buffer
, size_t size
)
2057 struct drm_dp_mst_port
*port
= container_of(aux
, struct drm_dp_mst_port
,
2060 return drm_dp_send_dpcd_write(port
->mgr
, port
,
2061 offset
, size
, buffer
);
2064 static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch
*mstb
, u8
*guid
)
2068 memcpy(mstb
->guid
, guid
, 16);
2070 if (!drm_dp_validate_guid(mstb
->mgr
, mstb
->guid
)) {
2071 if (mstb
->port_parent
) {
2072 ret
= drm_dp_send_dpcd_write(mstb
->mgr
,
2074 DP_GUID
, 16, mstb
->guid
);
2076 ret
= drm_dp_dpcd_write(mstb
->mgr
->aux
,
2077 DP_GUID
, mstb
->guid
, 16);
2081 if (ret
< 16 && ret
> 0)
2084 return ret
== 16 ? 0 : ret
;
2087 static void build_mst_prop_path(const struct drm_dp_mst_branch
*mstb
,
2090 size_t proppath_size
)
2094 snprintf(proppath
, proppath_size
, "mst:%d", mstb
->mgr
->conn_base_id
);
2095 for (i
= 0; i
< (mstb
->lct
- 1); i
++) {
2096 int shift
= (i
% 2) ? 0 : 4;
2097 int port_num
= (mstb
->rad
[i
/ 2] >> shift
) & 0xf;
2098 snprintf(temp
, sizeof(temp
), "-%d", port_num
);
2099 strlcat(proppath
, temp
, proppath_size
);
2101 snprintf(temp
, sizeof(temp
), "-%d", pnum
);
2102 strlcat(proppath
, temp
, proppath_size
);
2106 * drm_dp_mst_connector_late_register() - Late MST connector registration
2107 * @connector: The MST connector
2108 * @port: The MST port for this connector
2110 * Helper to register the remote aux device for this MST port. Drivers should
2111 * call this from their mst connector's late_register hook to enable MST aux
2114 * Return: 0 on success, negative error code on failure.
2116 int drm_dp_mst_connector_late_register(struct drm_connector
*connector
,
2117 struct drm_dp_mst_port
*port
)
2119 DRM_DEBUG_KMS("registering %s remote bus for %s\n",
2120 port
->aux
.name
, connector
->kdev
->kobj
.name
);
2122 port
->aux
.dev
= connector
->kdev
;
2123 return drm_dp_aux_register_devnode(&port
->aux
);
2125 EXPORT_SYMBOL(drm_dp_mst_connector_late_register
);
2128 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2129 * @connector: The MST connector
2130 * @port: The MST port for this connector
2132 * Helper to unregister the remote aux device for this MST port, registered by
2133 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2134 * connector's early_unregister hook.
2136 void drm_dp_mst_connector_early_unregister(struct drm_connector
*connector
,
2137 struct drm_dp_mst_port
*port
)
2139 DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
2140 port
->aux
.name
, connector
->kdev
->kobj
.name
);
2141 drm_dp_aux_unregister_devnode(&port
->aux
);
2143 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister
);
2146 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch
*mstb
,
2147 struct drm_dp_mst_port
*port
)
2149 struct drm_dp_mst_topology_mgr
*mgr
= port
->mgr
;
2153 build_mst_prop_path(mstb
, port
->port_num
, proppath
, sizeof(proppath
));
2154 port
->connector
= mgr
->cbs
->add_connector(mgr
, port
, proppath
);
2155 if (!port
->connector
) {
2160 if (port
->pdt
!= DP_PEER_DEVICE_NONE
&&
2161 drm_dp_mst_is_end_device(port
->pdt
, port
->mcs
)) {
2162 port
->cached_edid
= drm_get_edid(port
->connector
,
2164 drm_connector_set_tile_property(port
->connector
);
2167 drm_connector_register(port
->connector
);
2171 DRM_ERROR("Failed to create connector for port %p: %d\n", port
, ret
);
2175 * Drop a topology reference, and unlink the port from the in-memory topology
2179 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr
*mgr
,
2180 struct drm_dp_mst_port
*port
)
2182 mutex_lock(&mgr
->lock
);
2183 port
->parent
->num_ports
--;
2184 list_del(&port
->next
);
2185 mutex_unlock(&mgr
->lock
);
2186 drm_dp_mst_topology_put_port(port
);
2189 static struct drm_dp_mst_port
*
2190 drm_dp_mst_add_port(struct drm_device
*dev
,
2191 struct drm_dp_mst_topology_mgr
*mgr
,
2192 struct drm_dp_mst_branch
*mstb
, u8 port_number
)
2194 struct drm_dp_mst_port
*port
= kzalloc(sizeof(*port
), GFP_KERNEL
);
2199 kref_init(&port
->topology_kref
);
2200 kref_init(&port
->malloc_kref
);
2201 port
->parent
= mstb
;
2202 port
->port_num
= port_number
;
2204 port
->aux
.name
= "DPMST";
2205 port
->aux
.dev
= dev
->dev
;
2206 port
->aux
.is_remote
= true;
2208 /* initialize the MST downstream port's AUX crc work queue */
2209 drm_dp_remote_aux_init(&port
->aux
);
2212 * Make sure the memory allocation for our parent branch stays
2213 * around until our own memory allocation is released
2215 drm_dp_mst_get_mstb_malloc(mstb
);
2221 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch
*mstb
,
2222 struct drm_device
*dev
,
2223 struct drm_dp_link_addr_reply_port
*port_msg
)
2225 struct drm_dp_mst_topology_mgr
*mgr
= mstb
->mgr
;
2226 struct drm_dp_mst_port
*port
;
2227 int old_ddps
= 0, ret
;
2228 u8 new_pdt
= DP_PEER_DEVICE_NONE
;
2230 bool created
= false, send_link_addr
= false, changed
= false;
2232 port
= drm_dp_get_port(mstb
, port_msg
->port_number
);
2234 port
= drm_dp_mst_add_port(dev
, mgr
, mstb
,
2235 port_msg
->port_number
);
2240 } else if (!port
->input
&& port_msg
->input_port
&& port
->connector
) {
2241 /* Since port->connector can't be changed here, we create a
2242 * new port if input_port changes from 0 to 1
2244 drm_dp_mst_topology_unlink_port(mgr
, port
);
2245 drm_dp_mst_topology_put_port(port
);
2246 port
= drm_dp_mst_add_port(dev
, mgr
, mstb
,
2247 port_msg
->port_number
);
2252 } else if (port
->input
&& !port_msg
->input_port
) {
2254 } else if (port
->connector
) {
2255 /* We're updating a port that's exposed to userspace, so do it
2258 drm_modeset_lock(&mgr
->base
.lock
, NULL
);
2260 old_ddps
= port
->ddps
;
2261 changed
= port
->ddps
!= port_msg
->ddps
||
2263 (port
->ldps
!= port_msg
->legacy_device_plug_status
||
2264 port
->dpcd_rev
!= port_msg
->dpcd_revision
||
2265 port
->mcs
!= port_msg
->mcs
||
2266 port
->pdt
!= port_msg
->peer_device_type
||
2267 port
->num_sdp_stream_sinks
!=
2268 port_msg
->num_sdp_stream_sinks
));
2271 port
->input
= port_msg
->input_port
;
2273 new_pdt
= port_msg
->peer_device_type
;
2274 new_mcs
= port_msg
->mcs
;
2275 port
->ddps
= port_msg
->ddps
;
2276 port
->ldps
= port_msg
->legacy_device_plug_status
;
2277 port
->dpcd_rev
= port_msg
->dpcd_revision
;
2278 port
->num_sdp_streams
= port_msg
->num_sdp_streams
;
2279 port
->num_sdp_stream_sinks
= port_msg
->num_sdp_stream_sinks
;
2281 /* manage mstb port lists with mgr lock - take a reference
2284 mutex_lock(&mgr
->lock
);
2285 drm_dp_mst_topology_get_port(port
);
2286 list_add(&port
->next
, &mstb
->ports
);
2288 mutex_unlock(&mgr
->lock
);
2292 * Reprobe PBN caps on both hotplug, and when re-probing the link
2293 * for our parent mstb
2295 if (old_ddps
!= port
->ddps
|| !created
) {
2296 if (port
->ddps
&& !port
->input
) {
2297 ret
= drm_dp_send_enum_path_resources(mgr
, mstb
,
2306 ret
= drm_dp_port_set_pdt(port
, new_pdt
, new_mcs
);
2308 send_link_addr
= true;
2309 } else if (ret
< 0) {
2310 DRM_ERROR("Failed to change PDT on port %p: %d\n",
2316 * If this port wasn't just created, then we're reprobing because
2317 * we're coming out of suspend. In this case, always resend the link
2318 * address if there's an MSTB on this port
2320 if (!created
&& port
->pdt
== DP_PEER_DEVICE_MST_BRANCHING
&&
2322 send_link_addr
= true;
2324 if (port
->connector
)
2325 drm_modeset_unlock(&mgr
->base
.lock
);
2326 else if (!port
->input
)
2327 drm_dp_mst_port_add_connector(mstb
, port
);
2329 if (send_link_addr
&& port
->mstb
) {
2330 ret
= drm_dp_send_link_address(mgr
, port
->mstb
);
2331 if (ret
== 1) /* MSTB below us changed */
2337 /* put reference to this port */
2338 drm_dp_mst_topology_put_port(port
);
2342 drm_dp_mst_topology_unlink_port(mgr
, port
);
2343 if (port
->connector
)
2344 drm_modeset_unlock(&mgr
->base
.lock
);
2346 drm_dp_mst_topology_put_port(port
);
2351 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch
*mstb
,
2352 struct drm_dp_connection_status_notify
*conn_stat
)
2354 struct drm_dp_mst_topology_mgr
*mgr
= mstb
->mgr
;
2355 struct drm_dp_mst_port
*port
;
2356 int old_ddps
, old_input
, ret
, i
;
2359 bool dowork
= false, create_connector
= false;
2361 port
= drm_dp_get_port(mstb
, conn_stat
->port_number
);
2365 if (port
->connector
) {
2366 if (!port
->input
&& conn_stat
->input_port
) {
2368 * We can't remove a connector from an already exposed
2369 * port, so just throw the port out and make sure we
2370 * reprobe the link address of it's parent MSTB
2372 drm_dp_mst_topology_unlink_port(mgr
, port
);
2373 mstb
->link_address_sent
= false;
2378 /* Locking is only needed if the port's exposed to userspace */
2379 drm_modeset_lock(&mgr
->base
.lock
, NULL
);
2380 } else if (port
->input
&& !conn_stat
->input_port
) {
2381 create_connector
= true;
2382 /* Reprobe link address so we get num_sdp_streams */
2383 mstb
->link_address_sent
= false;
2387 old_ddps
= port
->ddps
;
2388 old_input
= port
->input
;
2389 port
->input
= conn_stat
->input_port
;
2390 port
->ldps
= conn_stat
->legacy_device_plug_status
;
2391 port
->ddps
= conn_stat
->displayport_device_plug_status
;
2393 if (old_ddps
!= port
->ddps
) {
2394 if (port
->ddps
&& !port
->input
)
2395 drm_dp_send_enum_path_resources(mgr
, mstb
, port
);
2400 new_pdt
= port
->input
? DP_PEER_DEVICE_NONE
: conn_stat
->peer_device_type
;
2401 new_mcs
= conn_stat
->message_capability_status
;
2402 ret
= drm_dp_port_set_pdt(port
, new_pdt
, new_mcs
);
2405 } else if (ret
< 0) {
2406 DRM_ERROR("Failed to change PDT for port %p: %d\n",
2411 if (!old_input
&& old_ddps
!= port
->ddps
&& !port
->ddps
) {
2412 for (i
= 0; i
< mgr
->max_payloads
; i
++) {
2413 struct drm_dp_vcpi
*vcpi
= mgr
->proposed_vcpis
[i
];
2414 struct drm_dp_mst_port
*port_validated
;
2420 container_of(vcpi
, struct drm_dp_mst_port
, vcpi
);
2422 drm_dp_mst_topology_get_port_validated(mgr
, port_validated
);
2423 if (!port_validated
) {
2424 mutex_lock(&mgr
->payload_lock
);
2425 vcpi
->num_slots
= 0;
2426 mutex_unlock(&mgr
->payload_lock
);
2428 drm_dp_mst_topology_put_port(port_validated
);
2433 if (port
->connector
)
2434 drm_modeset_unlock(&mgr
->base
.lock
);
2435 else if (create_connector
)
2436 drm_dp_mst_port_add_connector(mstb
, port
);
2439 drm_dp_mst_topology_put_port(port
);
2441 queue_work(system_long_wq
, &mstb
->mgr
->work
);
2444 static struct drm_dp_mst_branch
*drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr
*mgr
,
2447 struct drm_dp_mst_branch
*mstb
;
2448 struct drm_dp_mst_port
*port
;
2450 /* find the port by iterating down */
2452 mutex_lock(&mgr
->lock
);
2453 mstb
= mgr
->mst_primary
;
2458 for (i
= 0; i
< lct
- 1; i
++) {
2459 int shift
= (i
% 2) ? 0 : 4;
2460 int port_num
= (rad
[i
/ 2] >> shift
) & 0xf;
2462 list_for_each_entry(port
, &mstb
->ports
, next
) {
2463 if (port
->port_num
== port_num
) {
2466 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct
, rad
[0]);
2474 ret
= drm_dp_mst_topology_try_get_mstb(mstb
);
2478 mutex_unlock(&mgr
->lock
);
2482 static struct drm_dp_mst_branch
*get_mst_branch_device_by_guid_helper(
2483 struct drm_dp_mst_branch
*mstb
,
2484 const uint8_t *guid
)
2486 struct drm_dp_mst_branch
*found_mstb
;
2487 struct drm_dp_mst_port
*port
;
2489 if (memcmp(mstb
->guid
, guid
, 16) == 0)
2493 list_for_each_entry(port
, &mstb
->ports
, next
) {
2497 found_mstb
= get_mst_branch_device_by_guid_helper(port
->mstb
, guid
);
2506 static struct drm_dp_mst_branch
*
2507 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr
*mgr
,
2508 const uint8_t *guid
)
2510 struct drm_dp_mst_branch
*mstb
;
2513 /* find the port by iterating down */
2514 mutex_lock(&mgr
->lock
);
2516 mstb
= get_mst_branch_device_by_guid_helper(mgr
->mst_primary
, guid
);
2518 ret
= drm_dp_mst_topology_try_get_mstb(mstb
);
2523 mutex_unlock(&mgr
->lock
);
2527 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr
*mgr
,
2528 struct drm_dp_mst_branch
*mstb
)
2530 struct drm_dp_mst_port
*port
;
2532 bool changed
= false;
2534 if (!mstb
->link_address_sent
) {
2535 ret
= drm_dp_send_link_address(mgr
, mstb
);
2542 list_for_each_entry(port
, &mstb
->ports
, next
) {
2543 struct drm_dp_mst_branch
*mstb_child
= NULL
;
2545 if (port
->input
|| !port
->ddps
)
2549 mstb_child
= drm_dp_mst_topology_get_mstb_validated(
2553 ret
= drm_dp_check_and_send_link_address(mgr
,
2555 drm_dp_mst_topology_put_mstb(mstb_child
);
2566 static void drm_dp_mst_link_probe_work(struct work_struct
*work
)
2568 struct drm_dp_mst_topology_mgr
*mgr
=
2569 container_of(work
, struct drm_dp_mst_topology_mgr
, work
);
2570 struct drm_device
*dev
= mgr
->dev
;
2571 struct drm_dp_mst_branch
*mstb
;
2573 bool clear_payload_id_table
;
2575 mutex_lock(&mgr
->probe_lock
);
2577 mutex_lock(&mgr
->lock
);
2578 clear_payload_id_table
= !mgr
->payload_id_table_cleared
;
2579 mgr
->payload_id_table_cleared
= true;
2581 mstb
= mgr
->mst_primary
;
2583 ret
= drm_dp_mst_topology_try_get_mstb(mstb
);
2587 mutex_unlock(&mgr
->lock
);
2589 mutex_unlock(&mgr
->probe_lock
);
2594 * Certain branch devices seem to incorrectly report an available_pbn
2595 * of 0 on downstream sinks, even after clearing the
2596 * DP_PAYLOAD_ALLOCATE_* registers in
2597 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2598 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2599 * things work again.
2601 if (clear_payload_id_table
) {
2602 DRM_DEBUG_KMS("Clearing payload ID table\n");
2603 drm_dp_send_clear_payload_id_table(mgr
, mstb
);
2606 ret
= drm_dp_check_and_send_link_address(mgr
, mstb
);
2607 drm_dp_mst_topology_put_mstb(mstb
);
2609 mutex_unlock(&mgr
->probe_lock
);
2611 drm_kms_helper_hotplug_event(dev
);
2614 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr
*mgr
,
2619 if (memchr_inv(guid
, 0, 16))
2622 salt
= get_jiffies_64();
2624 memcpy(&guid
[0], &salt
, sizeof(u64
));
2625 memcpy(&guid
[8], &salt
, sizeof(u64
));
2630 static void build_dpcd_read(struct drm_dp_sideband_msg_tx
*msg
,
2631 u8 port_num
, u32 offset
, u8 num_bytes
)
2633 struct drm_dp_sideband_msg_req_body req
;
2635 req
.req_type
= DP_REMOTE_DPCD_READ
;
2636 req
.u
.dpcd_read
.port_number
= port_num
;
2637 req
.u
.dpcd_read
.dpcd_address
= offset
;
2638 req
.u
.dpcd_read
.num_bytes
= num_bytes
;
2639 drm_dp_encode_sideband_req(&req
, msg
);
2642 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr
*mgr
,
2643 bool up
, u8
*msg
, int len
)
2646 int regbase
= up
? DP_SIDEBAND_MSG_UP_REP_BASE
: DP_SIDEBAND_MSG_DOWN_REQ_BASE
;
2647 int tosend
, total
, offset
;
2654 tosend
= min3(mgr
->max_dpcd_transaction_bytes
, 16, total
);
2656 ret
= drm_dp_dpcd_write(mgr
->aux
, regbase
+ offset
,
2659 if (ret
!= tosend
) {
2660 if (ret
== -EIO
&& retries
< 5) {
2664 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend
, ret
);
2670 } while (total
> 0);
2674 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr
*hdr
,
2675 struct drm_dp_sideband_msg_tx
*txmsg
)
2677 struct drm_dp_mst_branch
*mstb
= txmsg
->dst
;
2680 req_type
= txmsg
->msg
[0] & 0x7f;
2681 if (req_type
== DP_CONNECTION_STATUS_NOTIFY
||
2682 req_type
== DP_RESOURCE_STATUS_NOTIFY
)
2686 hdr
->path_msg
= txmsg
->path_msg
;
2687 hdr
->lct
= mstb
->lct
;
2688 hdr
->lcr
= mstb
->lct
- 1;
2690 memcpy(hdr
->rad
, mstb
->rad
, mstb
->lct
/ 2);
2695 * process a single block of the next message in the sideband queue
2697 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr
*mgr
,
2698 struct drm_dp_sideband_msg_tx
*txmsg
,
2702 struct drm_dp_sideband_msg_hdr hdr
;
2703 int len
, space
, idx
, tosend
;
2706 if (txmsg
->state
== DRM_DP_SIDEBAND_TX_SENT
)
2709 memset(&hdr
, 0, sizeof(struct drm_dp_sideband_msg_hdr
));
2711 if (txmsg
->state
== DRM_DP_SIDEBAND_TX_QUEUED
)
2712 txmsg
->state
= DRM_DP_SIDEBAND_TX_START_SEND
;
2714 /* make hdr from dst mst */
2715 ret
= set_hdr_from_dst_qlock(&hdr
, txmsg
);
2719 /* amount left to send in this message */
2720 len
= txmsg
->cur_len
- txmsg
->cur_offset
;
2722 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2723 space
= 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr
);
2725 tosend
= min(len
, space
);
2726 if (len
== txmsg
->cur_len
)
2732 hdr
.msg_len
= tosend
+ 1;
2733 drm_dp_encode_sideband_msg_hdr(&hdr
, chunk
, &idx
);
2734 memcpy(&chunk
[idx
], &txmsg
->msg
[txmsg
->cur_offset
], tosend
);
2735 /* add crc at end */
2736 drm_dp_crc_sideband_chunk_req(&chunk
[idx
], tosend
);
2739 ret
= drm_dp_send_sideband_msg(mgr
, up
, chunk
, idx
);
2740 if (unlikely(ret
) && drm_debug_enabled(DRM_UT_DP
)) {
2741 struct drm_printer p
= drm_debug_printer(DBG_PREFIX
);
2743 drm_printf(&p
, "sideband msg failed to send\n");
2744 drm_dp_mst_dump_sideband_msg_tx(&p
, txmsg
);
2748 txmsg
->cur_offset
+= tosend
;
2749 if (txmsg
->cur_offset
== txmsg
->cur_len
) {
2750 txmsg
->state
= DRM_DP_SIDEBAND_TX_SENT
;
2756 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr
*mgr
)
2758 struct drm_dp_sideband_msg_tx
*txmsg
;
2761 WARN_ON(!mutex_is_locked(&mgr
->qlock
));
2763 /* construct a chunk from the first msg in the tx_msg queue */
2764 if (list_empty(&mgr
->tx_msg_downq
))
2767 txmsg
= list_first_entry(&mgr
->tx_msg_downq
,
2768 struct drm_dp_sideband_msg_tx
, next
);
2769 ret
= process_single_tx_qlock(mgr
, txmsg
, false);
2771 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret
);
2772 list_del(&txmsg
->next
);
2773 txmsg
->state
= DRM_DP_SIDEBAND_TX_TIMEOUT
;
2774 wake_up_all(&mgr
->tx_waitq
);
2778 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr
*mgr
,
2779 struct drm_dp_sideband_msg_tx
*txmsg
)
2781 mutex_lock(&mgr
->qlock
);
2782 list_add_tail(&txmsg
->next
, &mgr
->tx_msg_downq
);
2784 if (drm_debug_enabled(DRM_UT_DP
)) {
2785 struct drm_printer p
= drm_debug_printer(DBG_PREFIX
);
2787 drm_dp_mst_dump_sideband_msg_tx(&p
, txmsg
);
2790 if (list_is_singular(&mgr
->tx_msg_downq
))
2791 process_single_down_tx_qlock(mgr
);
2792 mutex_unlock(&mgr
->qlock
);
2796 drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply
*reply
)
2798 struct drm_dp_link_addr_reply_port
*port_reply
;
2801 for (i
= 0; i
< reply
->nports
; i
++) {
2802 port_reply
= &reply
->ports
[i
];
2803 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2805 port_reply
->input_port
,
2806 port_reply
->peer_device_type
,
2807 port_reply
->port_number
,
2808 port_reply
->dpcd_revision
,
2811 port_reply
->legacy_device_plug_status
,
2812 port_reply
->num_sdp_streams
,
2813 port_reply
->num_sdp_stream_sinks
);
2817 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr
*mgr
,
2818 struct drm_dp_mst_branch
*mstb
)
2820 struct drm_dp_sideband_msg_tx
*txmsg
;
2821 struct drm_dp_link_address_ack_reply
*reply
;
2822 struct drm_dp_mst_port
*port
, *tmp
;
2823 int i
, ret
, port_mask
= 0;
2824 bool changed
= false;
2826 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
2831 build_link_address(txmsg
);
2833 mstb
->link_address_sent
= true;
2834 drm_dp_queue_down_tx(mgr
, txmsg
);
2836 /* FIXME: Actually do some real error handling here */
2837 ret
= drm_dp_mst_wait_tx_reply(mstb
, txmsg
);
2839 DRM_ERROR("Sending link address failed with %d\n", ret
);
2842 if (txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
) {
2843 DRM_ERROR("link address NAK received\n");
2848 reply
= &txmsg
->reply
.u
.link_addr
;
2849 DRM_DEBUG_KMS("link address reply: %d\n", reply
->nports
);
2850 drm_dp_dump_link_address(reply
);
2852 ret
= drm_dp_check_mstb_guid(mstb
, reply
->guid
);
2856 drm_dp_mst_rad_to_str(mstb
->rad
, mstb
->lct
, buf
, sizeof(buf
));
2857 DRM_ERROR("GUID check on %s failed: %d\n",
2862 for (i
= 0; i
< reply
->nports
; i
++) {
2863 port_mask
|= BIT(reply
->ports
[i
].port_number
);
2864 ret
= drm_dp_mst_handle_link_address_port(mstb
, mgr
->dev
,
2872 /* Prune any ports that are currently a part of mstb in our in-memory
2873 * topology, but were not seen in this link address. Usually this
2874 * means that they were removed while the topology was out of sync,
2875 * e.g. during suspend/resume
2877 mutex_lock(&mgr
->lock
);
2878 list_for_each_entry_safe(port
, tmp
, &mstb
->ports
, next
) {
2879 if (port_mask
& BIT(port
->port_num
))
2882 DRM_DEBUG_KMS("port %d was not in link address, removing\n",
2884 list_del(&port
->next
);
2885 drm_dp_mst_topology_put_port(port
);
2888 mutex_unlock(&mgr
->lock
);
2892 mstb
->link_address_sent
= false;
2894 return ret
< 0 ? ret
: changed
;
2897 void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr
*mgr
,
2898 struct drm_dp_mst_branch
*mstb
)
2900 struct drm_dp_sideband_msg_tx
*txmsg
;
2903 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
2908 build_clear_payload_id_table(txmsg
);
2910 drm_dp_queue_down_tx(mgr
, txmsg
);
2912 ret
= drm_dp_mst_wait_tx_reply(mstb
, txmsg
);
2913 if (ret
> 0 && txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
)
2914 DRM_DEBUG_KMS("clear payload table id nak received\n");
2920 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr
*mgr
,
2921 struct drm_dp_mst_branch
*mstb
,
2922 struct drm_dp_mst_port
*port
)
2924 struct drm_dp_enum_path_resources_ack_reply
*path_res
;
2925 struct drm_dp_sideband_msg_tx
*txmsg
;
2928 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
2933 build_enum_path_resources(txmsg
, port
->port_num
);
2935 drm_dp_queue_down_tx(mgr
, txmsg
);
2937 ret
= drm_dp_mst_wait_tx_reply(mstb
, txmsg
);
2940 path_res
= &txmsg
->reply
.u
.path_resources
;
2942 if (txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
) {
2943 DRM_DEBUG_KMS("enum path resources nak received\n");
2945 if (port
->port_num
!= path_res
->port_number
)
2946 DRM_ERROR("got incorrect port in response\n");
2948 DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
2949 path_res
->port_number
,
2950 path_res
->full_payload_bw_number
,
2951 path_res
->avail_payload_bw_number
);
2954 * If something changed, make sure we send a
2957 if (port
->full_pbn
!= path_res
->full_payload_bw_number
||
2958 port
->fec_capable
!= path_res
->fec_capable
)
2961 port
->full_pbn
= path_res
->full_payload_bw_number
;
2962 port
->fec_capable
= path_res
->fec_capable
;
2970 static struct drm_dp_mst_port
*drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch
*mstb
)
2972 if (!mstb
->port_parent
)
2975 if (mstb
->port_parent
->mstb
!= mstb
)
2976 return mstb
->port_parent
;
2978 return drm_dp_get_last_connected_port_to_mstb(mstb
->port_parent
->parent
);
2982 * Searches upwards in the topology starting from mstb to try to find the
2983 * closest available parent of mstb that's still connected to the rest of the
2984 * topology. This can be used in order to perform operations like releasing
2985 * payloads, where the branch device which owned the payload may no longer be
2986 * around and thus would require that the payload on the last living relative
2989 static struct drm_dp_mst_branch
*
2990 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr
*mgr
,
2991 struct drm_dp_mst_branch
*mstb
,
2994 struct drm_dp_mst_branch
*rmstb
= NULL
;
2995 struct drm_dp_mst_port
*found_port
;
2997 mutex_lock(&mgr
->lock
);
2998 if (!mgr
->mst_primary
)
3002 found_port
= drm_dp_get_last_connected_port_to_mstb(mstb
);
3006 if (drm_dp_mst_topology_try_get_mstb(found_port
->parent
)) {
3007 rmstb
= found_port
->parent
;
3008 *port_num
= found_port
->port_num
;
3010 /* Search again, starting from this parent */
3011 mstb
= found_port
->parent
;
3015 mutex_unlock(&mgr
->lock
);
3019 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr
*mgr
,
3020 struct drm_dp_mst_port
*port
,
3024 struct drm_dp_sideband_msg_tx
*txmsg
;
3025 struct drm_dp_mst_branch
*mstb
;
3027 u8 sinks
[DRM_DP_MAX_SDP_STREAMS
];
3030 port_num
= port
->port_num
;
3031 mstb
= drm_dp_mst_topology_get_mstb_validated(mgr
, port
->parent
);
3033 mstb
= drm_dp_get_last_connected_port_and_mstb(mgr
,
3041 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
3047 for (i
= 0; i
< port
->num_sdp_streams
; i
++)
3051 build_allocate_payload(txmsg
, port_num
,
3053 pbn
, port
->num_sdp_streams
, sinks
);
3055 drm_dp_queue_down_tx(mgr
, txmsg
);
3058 * FIXME: there is a small chance that between getting the last
3059 * connected mstb and sending the payload message, the last connected
3060 * mstb could also be removed from the topology. In the future, this
3061 * needs to be fixed by restarting the
3062 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3063 * timeout if the topology is still connected to the system.
3065 ret
= drm_dp_mst_wait_tx_reply(mstb
, txmsg
);
3067 if (txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
)
3074 drm_dp_mst_topology_put_mstb(mstb
);
3078 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr
*mgr
,
3079 struct drm_dp_mst_port
*port
, bool power_up
)
3081 struct drm_dp_sideband_msg_tx
*txmsg
;
3084 port
= drm_dp_mst_topology_get_port_validated(mgr
, port
);
3088 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
3090 drm_dp_mst_topology_put_port(port
);
3094 txmsg
->dst
= port
->parent
;
3095 build_power_updown_phy(txmsg
, port
->port_num
, power_up
);
3096 drm_dp_queue_down_tx(mgr
, txmsg
);
3098 ret
= drm_dp_mst_wait_tx_reply(port
->parent
, txmsg
);
3100 if (txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
)
3106 drm_dp_mst_topology_put_port(port
);
3110 EXPORT_SYMBOL(drm_dp_send_power_updown_phy
);
3112 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr
*mgr
,
3114 struct drm_dp_payload
*payload
)
3118 ret
= drm_dp_dpcd_write_payload(mgr
, id
, payload
);
3120 payload
->payload_state
= 0;
3123 payload
->payload_state
= DP_PAYLOAD_LOCAL
;
3127 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr
*mgr
,
3128 struct drm_dp_mst_port
*port
,
3130 struct drm_dp_payload
*payload
)
3133 ret
= drm_dp_payload_send_msg(mgr
, port
, id
, port
->vcpi
.pbn
);
3136 payload
->payload_state
= DP_PAYLOAD_REMOTE
;
3140 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr
*mgr
,
3141 struct drm_dp_mst_port
*port
,
3143 struct drm_dp_payload
*payload
)
3145 DRM_DEBUG_KMS("\n");
3146 /* it's okay for these to fail */
3148 drm_dp_payload_send_msg(mgr
, port
, id
, 0);
3151 drm_dp_dpcd_write_payload(mgr
, id
, payload
);
3152 payload
->payload_state
= DP_PAYLOAD_DELETE_LOCAL
;
3156 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr
*mgr
,
3158 struct drm_dp_payload
*payload
)
3160 payload
->payload_state
= 0;
3165 * drm_dp_update_payload_part1() - Execute payload update part 1
3166 * @mgr: manager to use.
3168 * This iterates over all proposed virtual channels, and tries to
3169 * allocate space in the link for them. For 0->slots transitions,
3170 * this step just writes the VCPI to the MST device. For slots->0
3171 * transitions, this writes the updated VCPIs and removes the
3172 * remote VC payloads.
3174 * after calling this the driver should generate ACT and payload
3177 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr
*mgr
)
3179 struct drm_dp_payload req_payload
;
3180 struct drm_dp_mst_port
*port
;
3184 mutex_lock(&mgr
->payload_lock
);
3185 for (i
= 0; i
< mgr
->max_payloads
; i
++) {
3186 struct drm_dp_vcpi
*vcpi
= mgr
->proposed_vcpis
[i
];
3187 struct drm_dp_payload
*payload
= &mgr
->payloads
[i
];
3188 bool put_port
= false;
3190 /* solve the current payloads - compare to the hw ones
3191 - update the hw view */
3192 req_payload
.start_slot
= cur_slots
;
3194 port
= container_of(vcpi
, struct drm_dp_mst_port
,
3197 /* Validated ports don't matter if we're releasing
3200 if (vcpi
->num_slots
) {
3201 port
= drm_dp_mst_topology_get_port_validated(
3204 mutex_unlock(&mgr
->payload_lock
);
3210 req_payload
.num_slots
= vcpi
->num_slots
;
3211 req_payload
.vcpi
= vcpi
->vcpi
;
3214 req_payload
.num_slots
= 0;
3217 payload
->start_slot
= req_payload
.start_slot
;
3218 /* work out what is required to happen with this payload */
3219 if (payload
->num_slots
!= req_payload
.num_slots
) {
3221 /* need to push an update for this payload */
3222 if (req_payload
.num_slots
) {
3223 drm_dp_create_payload_step1(mgr
, vcpi
->vcpi
,
3225 payload
->num_slots
= req_payload
.num_slots
;
3226 payload
->vcpi
= req_payload
.vcpi
;
3228 } else if (payload
->num_slots
) {
3229 payload
->num_slots
= 0;
3230 drm_dp_destroy_payload_step1(mgr
, port
,
3233 req_payload
.payload_state
=
3234 payload
->payload_state
;
3235 payload
->start_slot
= 0;
3237 payload
->payload_state
= req_payload
.payload_state
;
3239 cur_slots
+= req_payload
.num_slots
;
3242 drm_dp_mst_topology_put_port(port
);
3245 for (i
= 0; i
< mgr
->max_payloads
; /* do nothing */) {
3246 if (mgr
->payloads
[i
].payload_state
!= DP_PAYLOAD_DELETE_LOCAL
) {
3251 DRM_DEBUG_KMS("removing payload %d\n", i
);
3252 for (j
= i
; j
< mgr
->max_payloads
- 1; j
++) {
3253 mgr
->payloads
[j
] = mgr
->payloads
[j
+ 1];
3254 mgr
->proposed_vcpis
[j
] = mgr
->proposed_vcpis
[j
+ 1];
3256 if (mgr
->proposed_vcpis
[j
] &&
3257 mgr
->proposed_vcpis
[j
]->num_slots
) {
3258 set_bit(j
+ 1, &mgr
->payload_mask
);
3260 clear_bit(j
+ 1, &mgr
->payload_mask
);
3264 memset(&mgr
->payloads
[mgr
->max_payloads
- 1], 0,
3265 sizeof(struct drm_dp_payload
));
3266 mgr
->proposed_vcpis
[mgr
->max_payloads
- 1] = NULL
;
3267 clear_bit(mgr
->max_payloads
, &mgr
->payload_mask
);
3269 mutex_unlock(&mgr
->payload_lock
);
3273 EXPORT_SYMBOL(drm_dp_update_payload_part1
);
3276 * drm_dp_update_payload_part2() - Execute payload update part 2
3277 * @mgr: manager to use.
3279 * This iterates over all proposed virtual channels, and tries to
3280 * allocate space in the link for them. For 0->slots transitions,
3281 * this step writes the remote VC payload commands. For slots->0
3282 * this just resets some internal state.
3284 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr
*mgr
)
3286 struct drm_dp_mst_port
*port
;
3289 mutex_lock(&mgr
->payload_lock
);
3290 for (i
= 0; i
< mgr
->max_payloads
; i
++) {
3292 if (!mgr
->proposed_vcpis
[i
])
3295 port
= container_of(mgr
->proposed_vcpis
[i
], struct drm_dp_mst_port
, vcpi
);
3297 DRM_DEBUG_KMS("payload %d %d\n", i
, mgr
->payloads
[i
].payload_state
);
3298 if (mgr
->payloads
[i
].payload_state
== DP_PAYLOAD_LOCAL
) {
3299 ret
= drm_dp_create_payload_step2(mgr
, port
, mgr
->proposed_vcpis
[i
]->vcpi
, &mgr
->payloads
[i
]);
3300 } else if (mgr
->payloads
[i
].payload_state
== DP_PAYLOAD_DELETE_LOCAL
) {
3301 ret
= drm_dp_destroy_payload_step2(mgr
, mgr
->proposed_vcpis
[i
]->vcpi
, &mgr
->payloads
[i
]);
3304 mutex_unlock(&mgr
->payload_lock
);
3308 mutex_unlock(&mgr
->payload_lock
);
3311 EXPORT_SYMBOL(drm_dp_update_payload_part2
);
3313 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr
*mgr
,
3314 struct drm_dp_mst_port
*port
,
3315 int offset
, int size
, u8
*bytes
)
3318 struct drm_dp_sideband_msg_tx
*txmsg
;
3319 struct drm_dp_mst_branch
*mstb
;
3321 mstb
= drm_dp_mst_topology_get_mstb_validated(mgr
, port
->parent
);
3325 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
3331 build_dpcd_read(txmsg
, port
->port_num
, offset
, size
);
3332 txmsg
->dst
= port
->parent
;
3334 drm_dp_queue_down_tx(mgr
, txmsg
);
3336 ret
= drm_dp_mst_wait_tx_reply(mstb
, txmsg
);
3340 /* DPCD read should never be NACKed */
3341 if (txmsg
->reply
.reply_type
== 1) {
3342 DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3343 mstb
, port
->port_num
, offset
, size
);
3348 if (txmsg
->reply
.u
.remote_dpcd_read_ack
.num_bytes
!= size
) {
3353 ret
= min_t(size_t, txmsg
->reply
.u
.remote_dpcd_read_ack
.num_bytes
,
3355 memcpy(bytes
, txmsg
->reply
.u
.remote_dpcd_read_ack
.bytes
, ret
);
3360 drm_dp_mst_topology_put_mstb(mstb
);
3365 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr
*mgr
,
3366 struct drm_dp_mst_port
*port
,
3367 int offset
, int size
, u8
*bytes
)
3370 struct drm_dp_sideband_msg_tx
*txmsg
;
3371 struct drm_dp_mst_branch
*mstb
;
3373 mstb
= drm_dp_mst_topology_get_mstb_validated(mgr
, port
->parent
);
3377 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
3383 build_dpcd_write(txmsg
, port
->port_num
, offset
, size
, bytes
);
3386 drm_dp_queue_down_tx(mgr
, txmsg
);
3388 ret
= drm_dp_mst_wait_tx_reply(mstb
, txmsg
);
3390 if (txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
)
3398 drm_dp_mst_topology_put_mstb(mstb
);
3402 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx
*msg
, u8 req_type
)
3404 struct drm_dp_sideband_msg_reply_body reply
;
3406 reply
.reply_type
= DP_SIDEBAND_REPLY_ACK
;
3407 reply
.req_type
= req_type
;
3408 drm_dp_encode_sideband_reply(&reply
, msg
);
3412 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr
*mgr
,
3413 struct drm_dp_mst_branch
*mstb
,
3414 int req_type
, bool broadcast
)
3416 struct drm_dp_sideband_msg_tx
*txmsg
;
3418 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
3423 drm_dp_encode_up_ack_reply(txmsg
, req_type
);
3425 mutex_lock(&mgr
->qlock
);
3426 /* construct a chunk from the first msg in the tx_msg queue */
3427 process_single_tx_qlock(mgr
, txmsg
, true);
3428 mutex_unlock(&mgr
->qlock
);
3434 static int drm_dp_get_vc_payload_bw(u8 dp_link_bw
, u8 dp_link_count
)
3436 if (dp_link_bw
== 0 || dp_link_count
== 0)
3437 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
3438 dp_link_bw
, dp_link_count
);
3440 return dp_link_bw
* dp_link_count
/ 2;
3444 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3445 * @mgr: manager to set state for
3446 * @mst_state: true to enable MST on this connector - false to disable.
3448 * This is called by the driver when it detects an MST capable device plugged
3449 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3451 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr
*mgr
, bool mst_state
)
3454 struct drm_dp_mst_branch
*mstb
= NULL
;
3456 mutex_lock(&mgr
->payload_lock
);
3457 mutex_lock(&mgr
->lock
);
3458 if (mst_state
== mgr
->mst_state
)
3461 mgr
->mst_state
= mst_state
;
3462 /* set the device into MST mode */
3464 struct drm_dp_payload reset_pay
;
3466 WARN_ON(mgr
->mst_primary
);
3469 ret
= drm_dp_dpcd_read(mgr
->aux
, DP_DPCD_REV
, mgr
->dpcd
, DP_RECEIVER_CAP_SIZE
);
3470 if (ret
!= DP_RECEIVER_CAP_SIZE
) {
3471 DRM_DEBUG_KMS("failed to read DPCD\n");
3475 mgr
->pbn_div
= drm_dp_get_vc_payload_bw(mgr
->dpcd
[1],
3476 mgr
->dpcd
[2] & DP_MAX_LANE_COUNT_MASK
);
3477 if (mgr
->pbn_div
== 0) {
3482 /* add initial branch device at LCT 1 */
3483 mstb
= drm_dp_add_mst_branch_device(1, NULL
);
3490 /* give this the main reference */
3491 mgr
->mst_primary
= mstb
;
3492 drm_dp_mst_topology_get_mstb(mgr
->mst_primary
);
3494 ret
= drm_dp_dpcd_writeb(mgr
->aux
, DP_MSTM_CTRL
,
3497 DP_UPSTREAM_IS_SRC
);
3501 reset_pay
.start_slot
= 0;
3502 reset_pay
.num_slots
= 0x3f;
3503 drm_dp_dpcd_write_payload(mgr
, 0, &reset_pay
);
3505 queue_work(system_long_wq
, &mgr
->work
);
3509 /* disable MST on the device */
3510 mstb
= mgr
->mst_primary
;
3511 mgr
->mst_primary
= NULL
;
3512 /* this can fail if the device is gone */
3513 drm_dp_dpcd_writeb(mgr
->aux
, DP_MSTM_CTRL
, 0);
3515 memset(mgr
->payloads
, 0,
3516 mgr
->max_payloads
* sizeof(mgr
->payloads
[0]));
3517 memset(mgr
->proposed_vcpis
, 0,
3518 mgr
->max_payloads
* sizeof(mgr
->proposed_vcpis
[0]));
3519 mgr
->payload_mask
= 0;
3520 set_bit(0, &mgr
->payload_mask
);
3522 mgr
->payload_id_table_cleared
= false;
3526 mutex_unlock(&mgr
->lock
);
3527 mutex_unlock(&mgr
->payload_lock
);
3529 drm_dp_mst_topology_put_mstb(mstb
);
3533 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst
);
3536 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch
*mstb
)
3538 struct drm_dp_mst_port
*port
;
3540 /* The link address will need to be re-sent on resume */
3541 mstb
->link_address_sent
= false;
3543 list_for_each_entry(port
, &mstb
->ports
, next
)
3545 drm_dp_mst_topology_mgr_invalidate_mstb(port
->mstb
);
3549 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3550 * @mgr: manager to suspend
3552 * This function tells the MST device that we can't handle UP messages
3553 * anymore. This should stop it from sending any since we are suspended.
3555 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr
*mgr
)
3557 mutex_lock(&mgr
->lock
);
3558 drm_dp_dpcd_writeb(mgr
->aux
, DP_MSTM_CTRL
,
3559 DP_MST_EN
| DP_UPSTREAM_IS_SRC
);
3560 mutex_unlock(&mgr
->lock
);
3561 flush_work(&mgr
->up_req_work
);
3562 flush_work(&mgr
->work
);
3563 flush_work(&mgr
->delayed_destroy_work
);
3565 mutex_lock(&mgr
->lock
);
3566 if (mgr
->mst_state
&& mgr
->mst_primary
)
3567 drm_dp_mst_topology_mgr_invalidate_mstb(mgr
->mst_primary
);
3568 mutex_unlock(&mgr
->lock
);
3570 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend
);
3573 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3574 * @mgr: manager to resume
3575 * @sync: whether or not to perform topology reprobing synchronously
3577 * This will fetch DPCD and see if the device is still there,
3578 * if it is, it will rewrite the MSTM control bits, and return.
3580 * If the device fails this returns -1, and the driver should do
3581 * a full MST reprobe, in case we were undocked.
3583 * During system resume (where it is assumed that the driver will be calling
3584 * drm_atomic_helper_resume()) this function should be called beforehand with
3585 * @sync set to true. In contexts like runtime resume where the driver is not
3586 * expected to be calling drm_atomic_helper_resume(), this function should be
3587 * called with @sync set to false in order to avoid deadlocking.
3589 * Returns: -1 if the MST topology was removed while we were suspended, 0
3592 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr
*mgr
,
3598 mutex_lock(&mgr
->lock
);
3599 if (!mgr
->mst_primary
)
3602 ret
= drm_dp_dpcd_read(mgr
->aux
, DP_DPCD_REV
, mgr
->dpcd
,
3603 DP_RECEIVER_CAP_SIZE
);
3604 if (ret
!= DP_RECEIVER_CAP_SIZE
) {
3605 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3609 ret
= drm_dp_dpcd_writeb(mgr
->aux
, DP_MSTM_CTRL
,
3612 DP_UPSTREAM_IS_SRC
);
3614 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
3618 /* Some hubs forget their guids after they resume */
3619 ret
= drm_dp_dpcd_read(mgr
->aux
, DP_GUID
, guid
, 16);
3621 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3625 ret
= drm_dp_check_mstb_guid(mgr
->mst_primary
, guid
);
3627 DRM_DEBUG_KMS("check mstb failed - undocked during suspend?\n");
3632 * For the final step of resuming the topology, we need to bring the
3633 * state of our in-memory topology back into sync with reality. So,
3634 * restart the probing process as if we're probing a new hub
3636 queue_work(system_long_wq
, &mgr
->work
);
3637 mutex_unlock(&mgr
->lock
);
3640 DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n");
3641 flush_work(&mgr
->work
);
3647 mutex_unlock(&mgr
->lock
);
3650 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume
);
3653 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr
*mgr
, bool up
,
3654 struct drm_dp_mst_branch
**mstb
)
3658 int replylen
, curreply
;
3661 struct drm_dp_sideband_msg_hdr hdr
;
3662 struct drm_dp_sideband_msg_rx
*msg
=
3663 up
? &mgr
->up_req_recv
: &mgr
->down_rep_recv
;
3664 int basereg
= up
? DP_SIDEBAND_MSG_UP_REQ_BASE
:
3665 DP_SIDEBAND_MSG_DOWN_REP_BASE
;
3670 len
= min(mgr
->max_dpcd_transaction_bytes
, 16);
3671 ret
= drm_dp_dpcd_read(mgr
->aux
, basereg
, replyblock
, len
);
3673 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len
, ret
);
3677 ret
= drm_dp_decode_sideband_msg_hdr(&hdr
, replyblock
, len
, &hdrlen
);
3679 print_hex_dump(KERN_DEBUG
, "failed hdr", DUMP_PREFIX_NONE
, 16,
3680 1, replyblock
, len
, false);
3681 DRM_DEBUG_KMS("ERROR: failed header\n");
3686 /* Caller is responsible for giving back this reference */
3687 *mstb
= drm_dp_get_mst_branch_device(mgr
, hdr
.lct
, hdr
.rad
);
3689 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3695 if (!drm_dp_sideband_msg_set_header(msg
, &hdr
, hdrlen
)) {
3696 DRM_DEBUG_KMS("sideband msg set header failed %d\n",
3701 replylen
= min(msg
->curchunk_len
, (u8
)(len
- hdrlen
));
3702 ret
= drm_dp_sideband_append_payload(msg
, replyblock
+ hdrlen
, replylen
);
3704 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock
[0]);
3708 replylen
= msg
->curchunk_len
+ msg
->curchunk_hdrlen
- len
;
3710 while (replylen
> 0) {
3711 len
= min3(replylen
, mgr
->max_dpcd_transaction_bytes
, 16);
3712 ret
= drm_dp_dpcd_read(mgr
->aux
, basereg
+ curreply
,
3715 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
3720 ret
= drm_dp_sideband_append_payload(msg
, replyblock
, len
);
3722 DRM_DEBUG_KMS("failed to build sideband msg\n");
3732 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr
*mgr
)
3734 struct drm_dp_sideband_msg_tx
*txmsg
;
3735 struct drm_dp_mst_branch
*mstb
= NULL
;
3736 struct drm_dp_sideband_msg_rx
*msg
= &mgr
->down_rep_recv
;
3738 if (!drm_dp_get_one_sb_msg(mgr
, false, &mstb
))
3741 /* Multi-packet message transmission, don't clear the reply */
3742 if (!msg
->have_eomt
)
3745 /* find the message */
3746 mutex_lock(&mgr
->qlock
);
3747 txmsg
= list_first_entry_or_null(&mgr
->tx_msg_downq
,
3748 struct drm_dp_sideband_msg_tx
, next
);
3749 mutex_unlock(&mgr
->qlock
);
3751 /* Were we actually expecting a response, and from this mstb? */
3752 if (!txmsg
|| txmsg
->dst
!= mstb
) {
3753 struct drm_dp_sideband_msg_hdr
*hdr
;
3754 hdr
= &msg
->initial_hdr
;
3755 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
3756 mstb
, hdr
->seqno
, hdr
->lct
, hdr
->rad
[0],
3758 goto out_clear_reply
;
3761 drm_dp_sideband_parse_reply(msg
, &txmsg
->reply
);
3763 if (txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
) {
3764 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3765 txmsg
->reply
.req_type
,
3766 drm_dp_mst_req_type_str(txmsg
->reply
.req_type
),
3767 txmsg
->reply
.u
.nak
.reason
,
3768 drm_dp_mst_nak_reason_str(txmsg
->reply
.u
.nak
.reason
),
3769 txmsg
->reply
.u
.nak
.nak_data
);
3772 memset(msg
, 0, sizeof(struct drm_dp_sideband_msg_rx
));
3773 drm_dp_mst_topology_put_mstb(mstb
);
3775 mutex_lock(&mgr
->qlock
);
3776 txmsg
->state
= DRM_DP_SIDEBAND_TX_RX
;
3777 list_del(&txmsg
->next
);
3778 mutex_unlock(&mgr
->qlock
);
3780 wake_up_all(&mgr
->tx_waitq
);
3785 memset(msg
, 0, sizeof(struct drm_dp_sideband_msg_rx
));
3788 drm_dp_mst_topology_put_mstb(mstb
);
3794 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr
*mgr
,
3795 struct drm_dp_pending_up_req
*up_req
)
3797 struct drm_dp_mst_branch
*mstb
= NULL
;
3798 struct drm_dp_sideband_msg_req_body
*msg
= &up_req
->msg
;
3799 struct drm_dp_sideband_msg_hdr
*hdr
= &up_req
->hdr
;
3800 bool hotplug
= false;
3802 if (hdr
->broadcast
) {
3803 const u8
*guid
= NULL
;
3805 if (msg
->req_type
== DP_CONNECTION_STATUS_NOTIFY
)
3806 guid
= msg
->u
.conn_stat
.guid
;
3807 else if (msg
->req_type
== DP_RESOURCE_STATUS_NOTIFY
)
3808 guid
= msg
->u
.resource_stat
.guid
;
3811 mstb
= drm_dp_get_mst_branch_device_by_guid(mgr
, guid
);
3813 mstb
= drm_dp_get_mst_branch_device(mgr
, hdr
->lct
, hdr
->rad
);
3817 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3822 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3823 if (msg
->req_type
== DP_CONNECTION_STATUS_NOTIFY
) {
3824 drm_dp_mst_handle_conn_stat(mstb
, &msg
->u
.conn_stat
);
3828 drm_dp_mst_topology_put_mstb(mstb
);
3832 static void drm_dp_mst_up_req_work(struct work_struct
*work
)
3834 struct drm_dp_mst_topology_mgr
*mgr
=
3835 container_of(work
, struct drm_dp_mst_topology_mgr
,
3837 struct drm_dp_pending_up_req
*up_req
;
3838 bool send_hotplug
= false;
3840 mutex_lock(&mgr
->probe_lock
);
3842 mutex_lock(&mgr
->up_req_lock
);
3843 up_req
= list_first_entry_or_null(&mgr
->up_req_list
,
3844 struct drm_dp_pending_up_req
,
3847 list_del(&up_req
->next
);
3848 mutex_unlock(&mgr
->up_req_lock
);
3853 send_hotplug
|= drm_dp_mst_process_up_req(mgr
, up_req
);
3856 mutex_unlock(&mgr
->probe_lock
);
3859 drm_kms_helper_hotplug_event(mgr
->dev
);
3862 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr
*mgr
)
3864 struct drm_dp_pending_up_req
*up_req
;
3866 if (!drm_dp_get_one_sb_msg(mgr
, true, NULL
))
3869 if (!mgr
->up_req_recv
.have_eomt
)
3872 up_req
= kzalloc(sizeof(*up_req
), GFP_KERNEL
);
3874 DRM_ERROR("Not enough memory to process MST up req\n");
3877 INIT_LIST_HEAD(&up_req
->next
);
3879 drm_dp_sideband_parse_req(&mgr
->up_req_recv
, &up_req
->msg
);
3881 if (up_req
->msg
.req_type
!= DP_CONNECTION_STATUS_NOTIFY
&&
3882 up_req
->msg
.req_type
!= DP_RESOURCE_STATUS_NOTIFY
) {
3883 DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n",
3884 up_req
->msg
.req_type
);
3889 drm_dp_send_up_ack_reply(mgr
, mgr
->mst_primary
, up_req
->msg
.req_type
,
3892 if (up_req
->msg
.req_type
== DP_CONNECTION_STATUS_NOTIFY
) {
3893 const struct drm_dp_connection_status_notify
*conn_stat
=
3894 &up_req
->msg
.u
.conn_stat
;
3896 DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
3897 conn_stat
->port_number
,
3898 conn_stat
->legacy_device_plug_status
,
3899 conn_stat
->displayport_device_plug_status
,
3900 conn_stat
->message_capability_status
,
3901 conn_stat
->input_port
,
3902 conn_stat
->peer_device_type
);
3903 } else if (up_req
->msg
.req_type
== DP_RESOURCE_STATUS_NOTIFY
) {
3904 const struct drm_dp_resource_status_notify
*res_stat
=
3905 &up_req
->msg
.u
.resource_stat
;
3907 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
3908 res_stat
->port_number
,
3909 res_stat
->available_pbn
);
3912 up_req
->hdr
= mgr
->up_req_recv
.initial_hdr
;
3913 mutex_lock(&mgr
->up_req_lock
);
3914 list_add_tail(&up_req
->next
, &mgr
->up_req_list
);
3915 mutex_unlock(&mgr
->up_req_lock
);
3916 queue_work(system_long_wq
, &mgr
->up_req_work
);
3919 memset(&mgr
->up_req_recv
, 0, sizeof(struct drm_dp_sideband_msg_rx
));
3924 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
3925 * @mgr: manager to notify irq for.
3926 * @esi: 4 bytes from SINK_COUNT_ESI
3927 * @handled: whether the hpd interrupt was consumed or not
3929 * This should be called from the driver when it detects a short IRQ,
3930 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
3931 * topology manager will process the sideband messages received as a result
3934 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr
*mgr
, u8
*esi
, bool *handled
)
3941 if (sc
!= mgr
->sink_count
) {
3942 mgr
->sink_count
= sc
;
3946 if (esi
[1] & DP_DOWN_REP_MSG_RDY
) {
3947 ret
= drm_dp_mst_handle_down_rep(mgr
);
3951 if (esi
[1] & DP_UP_REQ_MSG_RDY
) {
3952 ret
|= drm_dp_mst_handle_up_req(mgr
);
3956 drm_dp_mst_kick_tx(mgr
);
3959 EXPORT_SYMBOL(drm_dp_mst_hpd_irq
);
3962 * drm_dp_mst_detect_port() - get connection status for an MST port
3963 * @connector: DRM connector for this port
3964 * @ctx: The acquisition context to use for grabbing locks
3965 * @mgr: manager for this port
3966 * @port: pointer to a port
3968 * This returns the current connection state for a port.
3971 drm_dp_mst_detect_port(struct drm_connector
*connector
,
3972 struct drm_modeset_acquire_ctx
*ctx
,
3973 struct drm_dp_mst_topology_mgr
*mgr
,
3974 struct drm_dp_mst_port
*port
)
3978 /* we need to search for the port in the mgr in case it's gone */
3979 port
= drm_dp_mst_topology_get_port_validated(mgr
, port
);
3981 return connector_status_disconnected
;
3983 ret
= drm_modeset_lock(&mgr
->base
.lock
, ctx
);
3987 ret
= connector_status_disconnected
;
3992 switch (port
->pdt
) {
3993 case DP_PEER_DEVICE_NONE
:
3994 case DP_PEER_DEVICE_MST_BRANCHING
:
3996 ret
= connector_status_connected
;
3999 case DP_PEER_DEVICE_SST_SINK
:
4000 ret
= connector_status_connected
;
4001 /* for logical ports - cache the EDID */
4002 if (port
->port_num
>= 8 && !port
->cached_edid
) {
4003 port
->cached_edid
= drm_get_edid(connector
, &port
->aux
.ddc
);
4006 case DP_PEER_DEVICE_DP_LEGACY_CONV
:
4008 ret
= connector_status_connected
;
4012 drm_dp_mst_topology_put_port(port
);
4015 EXPORT_SYMBOL(drm_dp_mst_detect_port
);
4018 * drm_dp_mst_get_edid() - get EDID for an MST port
4019 * @connector: toplevel connector to get EDID for
4020 * @mgr: manager for this port
4021 * @port: unverified pointer to a port.
4023 * This returns an EDID for the port connected to a connector,
4024 * It validates the pointer still exists so the caller doesn't require a
4027 struct edid
*drm_dp_mst_get_edid(struct drm_connector
*connector
, struct drm_dp_mst_topology_mgr
*mgr
, struct drm_dp_mst_port
*port
)
4029 struct edid
*edid
= NULL
;
4031 /* we need to search for the port in the mgr in case it's gone */
4032 port
= drm_dp_mst_topology_get_port_validated(mgr
, port
);
4036 if (port
->cached_edid
)
4037 edid
= drm_edid_duplicate(port
->cached_edid
);
4039 edid
= drm_get_edid(connector
, &port
->aux
.ddc
);
4041 port
->has_audio
= drm_detect_monitor_audio(edid
);
4042 drm_dp_mst_topology_put_port(port
);
4045 EXPORT_SYMBOL(drm_dp_mst_get_edid
);
4048 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4049 * @mgr: manager to use
4050 * @pbn: payload bandwidth to convert into slots.
4052 * Calculate the number of VCPI slots that will be required for the given PBN
4053 * value. This function is deprecated, and should not be used in atomic
4057 * The total slots required for this port, or error.
4059 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr
*mgr
,
4064 num_slots
= DIV_ROUND_UP(pbn
, mgr
->pbn_div
);
4066 /* max. time slots - one slot for MTP header */
4071 EXPORT_SYMBOL(drm_dp_find_vcpi_slots
);
4073 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr
*mgr
,
4074 struct drm_dp_vcpi
*vcpi
, int pbn
, int slots
)
4078 /* max. time slots - one slot for MTP header */
4083 vcpi
->aligned_pbn
= slots
* mgr
->pbn_div
;
4084 vcpi
->num_slots
= slots
;
4086 ret
= drm_dp_mst_assign_payload_id(mgr
, vcpi
);
4093 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4094 * @state: global atomic state
4095 * @mgr: MST topology manager for the port
4096 * @port: port to find vcpi slots for
4097 * @pbn: bandwidth required for the mode in PBN
4098 * @pbn_div: divider for DSC mode that takes FEC into account
4100 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4101 * may have had. Any atomic drivers which support MST must call this function
4102 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4103 * current VCPI allocation for the new state, but only when
4104 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4105 * to ensure compatibility with userspace applications that still use the
4106 * legacy modesetting UAPI.
4108 * Allocations set by this function are not checked against the bandwidth
4109 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4111 * Additionally, it is OK to call this function multiple times on the same
4112 * @port as needed. It is not OK however, to call this function and
4113 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4116 * drm_dp_atomic_release_vcpi_slots()
4117 * drm_dp_mst_atomic_check()
4120 * Total slots in the atomic state assigned for this port, or a negative error
4121 * code if the port no longer exists
4123 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state
*state
,
4124 struct drm_dp_mst_topology_mgr
*mgr
,
4125 struct drm_dp_mst_port
*port
, int pbn
,
4128 struct drm_dp_mst_topology_state
*topology_state
;
4129 struct drm_dp_vcpi_allocation
*pos
, *vcpi
= NULL
;
4130 int prev_slots
, prev_bw
, req_slots
;
4132 topology_state
= drm_atomic_get_mst_topology_state(state
, mgr
);
4133 if (IS_ERR(topology_state
))
4134 return PTR_ERR(topology_state
);
4136 /* Find the current allocation for this port, if any */
4137 list_for_each_entry(pos
, &topology_state
->vcpis
, next
) {
4138 if (pos
->port
== port
) {
4140 prev_slots
= vcpi
->vcpi
;
4141 prev_bw
= vcpi
->pbn
;
4144 * This should never happen, unless the driver tries
4145 * releasing and allocating the same VCPI allocation,
4148 if (WARN_ON(!prev_slots
)) {
4149 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4163 pbn_div
= mgr
->pbn_div
;
4165 req_slots
= DIV_ROUND_UP(pbn
, pbn_div
);
4167 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4168 port
->connector
->base
.id
, port
->connector
->name
,
4169 port
, prev_slots
, req_slots
);
4170 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4171 port
->connector
->base
.id
, port
->connector
->name
,
4172 port
, prev_bw
, pbn
);
4174 /* Add the new allocation to the state */
4176 vcpi
= kzalloc(sizeof(*vcpi
), GFP_KERNEL
);
4180 drm_dp_mst_get_port_malloc(port
);
4182 list_add(&vcpi
->next
, &topology_state
->vcpis
);
4184 vcpi
->vcpi
= req_slots
;
4189 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots
);
4192 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4193 * @state: global atomic state
4194 * @mgr: MST topology manager for the port
4195 * @port: The port to release the VCPI slots from
4197 * Releases any VCPI slots that have been allocated to a port in the atomic
4198 * state. Any atomic drivers which support MST must call this function in
4199 * their &drm_connector_helper_funcs.atomic_check() callback when the
4200 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4201 * removed) when it had VCPI allocated in the previous atomic state.
4203 * It is OK to call this even if @port has been removed from the system.
4204 * Additionally, it is OK to call this function multiple times on the same
4205 * @port as needed. It is not OK however, to call this function and
4206 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4210 * drm_dp_atomic_find_vcpi_slots()
4211 * drm_dp_mst_atomic_check()
4214 * 0 if all slots for this port were added back to
4215 * &drm_dp_mst_topology_state.avail_slots or negative error code
4217 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state
*state
,
4218 struct drm_dp_mst_topology_mgr
*mgr
,
4219 struct drm_dp_mst_port
*port
)
4221 struct drm_dp_mst_topology_state
*topology_state
;
4222 struct drm_dp_vcpi_allocation
*pos
;
4225 topology_state
= drm_atomic_get_mst_topology_state(state
, mgr
);
4226 if (IS_ERR(topology_state
))
4227 return PTR_ERR(topology_state
);
4229 list_for_each_entry(pos
, &topology_state
->vcpis
, next
) {
4230 if (pos
->port
== port
) {
4235 if (WARN_ON(!found
)) {
4236 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
4237 port
, &topology_state
->base
);
4241 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port
, pos
->vcpi
);
4243 drm_dp_mst_put_port_malloc(port
);
4250 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots
);
4253 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4254 * @mgr: manager for this port
4255 * @port: port to allocate a virtual channel for.
4256 * @pbn: payload bandwidth number to request
4257 * @slots: returned number of slots for this PBN.
4259 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr
*mgr
,
4260 struct drm_dp_mst_port
*port
, int pbn
, int slots
)
4264 port
= drm_dp_mst_topology_get_port_validated(mgr
, port
);
4271 if (port
->vcpi
.vcpi
> 0) {
4272 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4273 port
->vcpi
.vcpi
, port
->vcpi
.pbn
, pbn
);
4274 if (pbn
== port
->vcpi
.pbn
) {
4275 drm_dp_mst_topology_put_port(port
);
4280 ret
= drm_dp_init_vcpi(mgr
, &port
->vcpi
, pbn
, slots
);
4282 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
4283 DIV_ROUND_UP(pbn
, mgr
->pbn_div
), ret
);
4286 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
4287 pbn
, port
->vcpi
.num_slots
);
4289 /* Keep port allocated until its payload has been removed */
4290 drm_dp_mst_get_port_malloc(port
);
4291 drm_dp_mst_topology_put_port(port
);
4296 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi
);
4298 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr
*mgr
, struct drm_dp_mst_port
*port
)
4301 port
= drm_dp_mst_topology_get_port_validated(mgr
, port
);
4305 slots
= port
->vcpi
.num_slots
;
4306 drm_dp_mst_topology_put_port(port
);
4309 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots
);
4312 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4313 * @mgr: manager for this port
4314 * @port: unverified pointer to a port.
4316 * This just resets the number of slots for the ports VCPI for later programming.
4318 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr
*mgr
, struct drm_dp_mst_port
*port
)
4321 * A port with VCPI will remain allocated until its VCPI is
4322 * released, no verified ref needed
4325 port
->vcpi
.num_slots
= 0;
4327 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots
);
4330 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4331 * @mgr: manager for this port
4332 * @port: port to deallocate vcpi for
4334 * This can be called unconditionally, regardless of whether
4335 * drm_dp_mst_allocate_vcpi() succeeded or not.
4337 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr
*mgr
,
4338 struct drm_dp_mst_port
*port
)
4340 if (!port
->vcpi
.vcpi
)
4343 drm_dp_mst_put_payload_id(mgr
, port
->vcpi
.vcpi
);
4344 port
->vcpi
.num_slots
= 0;
4346 port
->vcpi
.aligned_pbn
= 0;
4347 port
->vcpi
.vcpi
= 0;
4348 drm_dp_mst_put_port_malloc(port
);
4350 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi
);
4352 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr
*mgr
,
4353 int id
, struct drm_dp_payload
*payload
)
4355 u8 payload_alloc
[3], status
;
4359 drm_dp_dpcd_writeb(mgr
->aux
, DP_PAYLOAD_TABLE_UPDATE_STATUS
,
4360 DP_PAYLOAD_TABLE_UPDATED
);
4362 payload_alloc
[0] = id
;
4363 payload_alloc
[1] = payload
->start_slot
;
4364 payload_alloc
[2] = payload
->num_slots
;
4366 ret
= drm_dp_dpcd_write(mgr
->aux
, DP_PAYLOAD_ALLOCATE_SET
, payload_alloc
, 3);
4368 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret
);
4373 ret
= drm_dp_dpcd_readb(mgr
->aux
, DP_PAYLOAD_TABLE_UPDATE_STATUS
, &status
);
4375 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret
);
4379 if (!(status
& DP_PAYLOAD_TABLE_UPDATED
)) {
4382 usleep_range(10000, 20000);
4385 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status
);
4394 static int do_get_act_status(struct drm_dp_aux
*aux
)
4399 ret
= drm_dp_dpcd_readb(aux
, DP_PAYLOAD_TABLE_UPDATE_STATUS
, &status
);
4407 * drm_dp_check_act_status() - Polls for ACT handled status.
4408 * @mgr: manager to use
4410 * Tries waiting for the MST hub to finish updating it's payload table by
4411 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4415 * 0 if the ACT was handled in time, negative error code on failure.
4417 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr
*mgr
)
4420 * There doesn't seem to be any recommended retry count or timeout in
4421 * the MST specification. Since some hubs have been observed to take
4422 * over 1 second to update their payload allocations under certain
4423 * conditions, we use a rather large timeout value.
4425 const int timeout_ms
= 3000;
4428 ret
= readx_poll_timeout(do_get_act_status
, mgr
->aux
, status
,
4429 status
& DP_PAYLOAD_ACT_HANDLED
|| status
< 0,
4430 200, timeout_ms
* USEC_PER_MSEC
);
4431 if (ret
< 0 && status
>= 0) {
4432 DRM_ERROR("Failed to get ACT after %dms, last status: %02x\n",
4433 timeout_ms
, status
);
4435 } else if (status
< 0) {
4437 * Failure here isn't unexpected - the hub may have
4438 * just been unplugged
4440 DRM_DEBUG_KMS("Failed to read payload table status: %d\n",
4447 EXPORT_SYMBOL(drm_dp_check_act_status
);
4450 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4451 * @clock: dot clock for the mode
4452 * @bpp: bpp for the mode.
4453 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4455 * This uses the formula in the spec to calculate the PBN value for a mode.
4457 int drm_dp_calc_pbn_mode(int clock
, int bpp
, bool dsc
)
4460 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4461 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4462 * common multiplier to render an integer PBN for all link rate/lane
4463 * counts combinations
4465 * peak_kbps *= (1006/1000)
4466 * peak_kbps *= (64/54)
4467 * peak_kbps *= 8 convert to bytes
4469 * If the bpp is in units of 1/16, further divide by 16. Put this
4470 * factor in the numerator rather than the denominator to avoid
4475 return DIV_ROUND_UP_ULL(mul_u32_u32(clock
* (bpp
/ 16), 64 * 1006),
4476 8 * 54 * 1000 * 1000);
4478 return DIV_ROUND_UP_ULL(mul_u32_u32(clock
* bpp
, 64 * 1006),
4479 8 * 54 * 1000 * 1000);
4481 EXPORT_SYMBOL(drm_dp_calc_pbn_mode
);
4483 /* we want to kick the TX after we've ack the up/down IRQs. */
4484 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr
*mgr
)
4486 queue_work(system_long_wq
, &mgr
->tx_work
);
4489 static void drm_dp_mst_dump_mstb(struct seq_file
*m
,
4490 struct drm_dp_mst_branch
*mstb
)
4492 struct drm_dp_mst_port
*port
;
4493 int tabs
= mstb
->lct
;
4497 for (i
= 0; i
< tabs
; i
++)
4501 seq_printf(m
, "%smst: %p, %d\n", prefix
, mstb
, mstb
->num_ports
);
4502 list_for_each_entry(port
, &mstb
->ports
, next
) {
4503 seq_printf(m
, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix
, port
->port_num
, port
->input
, port
->pdt
, port
->ddps
, port
->ldps
, port
->num_sdp_streams
, port
->num_sdp_stream_sinks
, port
, port
->connector
);
4505 drm_dp_mst_dump_mstb(m
, port
->mstb
);
4509 #define DP_PAYLOAD_TABLE_SIZE 64
4511 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr
*mgr
,
4516 for (i
= 0; i
< DP_PAYLOAD_TABLE_SIZE
; i
+= 16) {
4517 if (drm_dp_dpcd_read(mgr
->aux
,
4518 DP_PAYLOAD_TABLE_UPDATE_STATUS
+ i
,
4525 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr
*mgr
,
4526 struct drm_dp_mst_port
*port
, char *name
,
4529 struct edid
*mst_edid
;
4531 mst_edid
= drm_dp_mst_get_edid(port
->connector
, mgr
, port
);
4532 drm_edid_get_monitor_name(mst_edid
, name
, namelen
);
4536 * drm_dp_mst_dump_topology(): dump topology to seq file.
4537 * @m: seq_file to dump output to
4538 * @mgr: manager to dump current topology for.
4540 * helper to dump MST topology to a seq file for debugfs.
4542 void drm_dp_mst_dump_topology(struct seq_file
*m
,
4543 struct drm_dp_mst_topology_mgr
*mgr
)
4546 struct drm_dp_mst_port
*port
;
4548 mutex_lock(&mgr
->lock
);
4549 if (mgr
->mst_primary
)
4550 drm_dp_mst_dump_mstb(m
, mgr
->mst_primary
);
4553 mutex_unlock(&mgr
->lock
);
4555 mutex_lock(&mgr
->payload_lock
);
4556 seq_printf(m
, "vcpi: %lx %lx %d\n", mgr
->payload_mask
, mgr
->vcpi_mask
,
4559 for (i
= 0; i
< mgr
->max_payloads
; i
++) {
4560 if (mgr
->proposed_vcpis
[i
]) {
4563 port
= container_of(mgr
->proposed_vcpis
[i
], struct drm_dp_mst_port
, vcpi
);
4564 fetch_monitor_name(mgr
, port
, name
, sizeof(name
));
4565 seq_printf(m
, "vcpi %d: %d %d %d sink name: %s\n", i
,
4566 port
->port_num
, port
->vcpi
.vcpi
,
4567 port
->vcpi
.num_slots
,
4568 (*name
!= 0) ? name
: "Unknown");
4570 seq_printf(m
, "vcpi %d:unused\n", i
);
4572 for (i
= 0; i
< mgr
->max_payloads
; i
++) {
4573 seq_printf(m
, "payload %d: %d, %d, %d\n",
4575 mgr
->payloads
[i
].payload_state
,
4576 mgr
->payloads
[i
].start_slot
,
4577 mgr
->payloads
[i
].num_slots
);
4581 mutex_unlock(&mgr
->payload_lock
);
4583 mutex_lock(&mgr
->lock
);
4584 if (mgr
->mst_primary
) {
4585 u8 buf
[DP_PAYLOAD_TABLE_SIZE
];
4588 ret
= drm_dp_dpcd_read(mgr
->aux
, DP_DPCD_REV
, buf
, DP_RECEIVER_CAP_SIZE
);
4590 seq_printf(m
, "dpcd read failed\n");
4593 seq_printf(m
, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE
, buf
);
4595 ret
= drm_dp_dpcd_read(mgr
->aux
, DP_FAUX_CAP
, buf
, 2);
4597 seq_printf(m
, "faux/mst read failed\n");
4600 seq_printf(m
, "faux/mst: %*ph\n", 2, buf
);
4602 ret
= drm_dp_dpcd_read(mgr
->aux
, DP_MSTM_CTRL
, buf
, 1);
4604 seq_printf(m
, "mst ctrl read failed\n");
4607 seq_printf(m
, "mst ctrl: %*ph\n", 1, buf
);
4609 /* dump the standard OUI branch header */
4610 ret
= drm_dp_dpcd_read(mgr
->aux
, DP_BRANCH_OUI
, buf
, DP_BRANCH_OUI_HEADER_SIZE
);
4612 seq_printf(m
, "branch oui read failed\n");
4615 seq_printf(m
, "branch oui: %*phN devid: ", 3, buf
);
4617 for (i
= 0x3; i
< 0x8 && buf
[i
]; i
++)
4618 seq_printf(m
, "%c", buf
[i
]);
4619 seq_printf(m
, " revision: hw: %x.%x sw: %x.%x\n",
4620 buf
[0x9] >> 4, buf
[0x9] & 0xf, buf
[0xa], buf
[0xb]);
4621 if (dump_dp_payload_table(mgr
, buf
))
4622 seq_printf(m
, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE
, buf
);
4626 mutex_unlock(&mgr
->lock
);
4629 EXPORT_SYMBOL(drm_dp_mst_dump_topology
);
4631 static void drm_dp_tx_work(struct work_struct
*work
)
4633 struct drm_dp_mst_topology_mgr
*mgr
= container_of(work
, struct drm_dp_mst_topology_mgr
, tx_work
);
4635 mutex_lock(&mgr
->qlock
);
4636 if (!list_empty(&mgr
->tx_msg_downq
))
4637 process_single_down_tx_qlock(mgr
);
4638 mutex_unlock(&mgr
->qlock
);
4642 drm_dp_delayed_destroy_port(struct drm_dp_mst_port
*port
)
4644 if (port
->connector
) {
4645 drm_connector_unregister(port
->connector
);
4646 drm_connector_put(port
->connector
);
4649 drm_dp_port_set_pdt(port
, DP_PEER_DEVICE_NONE
, port
->mcs
);
4650 drm_dp_mst_put_port_malloc(port
);
4654 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch
*mstb
)
4656 struct drm_dp_mst_topology_mgr
*mgr
= mstb
->mgr
;
4657 struct drm_dp_mst_port
*port
, *port_tmp
;
4658 struct drm_dp_sideband_msg_tx
*txmsg
, *txmsg_tmp
;
4659 bool wake_tx
= false;
4661 mutex_lock(&mgr
->lock
);
4662 list_for_each_entry_safe(port
, port_tmp
, &mstb
->ports
, next
) {
4663 list_del(&port
->next
);
4664 drm_dp_mst_topology_put_port(port
);
4666 mutex_unlock(&mgr
->lock
);
4668 /* drop any tx slot msg */
4669 mutex_lock(&mstb
->mgr
->qlock
);
4670 list_for_each_entry_safe(txmsg
, txmsg_tmp
, &mgr
->tx_msg_downq
, next
) {
4671 if (txmsg
->dst
!= mstb
)
4674 txmsg
->state
= DRM_DP_SIDEBAND_TX_TIMEOUT
;
4675 list_del(&txmsg
->next
);
4678 mutex_unlock(&mstb
->mgr
->qlock
);
4681 wake_up_all(&mstb
->mgr
->tx_waitq
);
4683 drm_dp_mst_put_mstb_malloc(mstb
);
4686 static void drm_dp_delayed_destroy_work(struct work_struct
*work
)
4688 struct drm_dp_mst_topology_mgr
*mgr
=
4689 container_of(work
, struct drm_dp_mst_topology_mgr
,
4690 delayed_destroy_work
);
4691 bool send_hotplug
= false, go_again
;
4694 * Not a regular list traverse as we have to drop the destroy
4695 * connector lock before destroying the mstb/port, to avoid AB->BA
4696 * ordering between this lock and the config mutex.
4702 struct drm_dp_mst_branch
*mstb
;
4704 mutex_lock(&mgr
->delayed_destroy_lock
);
4705 mstb
= list_first_entry_or_null(&mgr
->destroy_branch_device_list
,
4706 struct drm_dp_mst_branch
,
4709 list_del(&mstb
->destroy_next
);
4710 mutex_unlock(&mgr
->delayed_destroy_lock
);
4715 drm_dp_delayed_destroy_mstb(mstb
);
4720 struct drm_dp_mst_port
*port
;
4722 mutex_lock(&mgr
->delayed_destroy_lock
);
4723 port
= list_first_entry_or_null(&mgr
->destroy_port_list
,
4724 struct drm_dp_mst_port
,
4727 list_del(&port
->next
);
4728 mutex_unlock(&mgr
->delayed_destroy_lock
);
4733 drm_dp_delayed_destroy_port(port
);
4734 send_hotplug
= true;
4740 drm_kms_helper_hotplug_event(mgr
->dev
);
4743 static struct drm_private_state
*
4744 drm_dp_mst_duplicate_state(struct drm_private_obj
*obj
)
4746 struct drm_dp_mst_topology_state
*state
, *old_state
=
4747 to_dp_mst_topology_state(obj
->state
);
4748 struct drm_dp_vcpi_allocation
*pos
, *vcpi
;
4750 state
= kmemdup(old_state
, sizeof(*state
), GFP_KERNEL
);
4754 __drm_atomic_helper_private_obj_duplicate_state(obj
, &state
->base
);
4756 INIT_LIST_HEAD(&state
->vcpis
);
4758 list_for_each_entry(pos
, &old_state
->vcpis
, next
) {
4759 /* Prune leftover freed VCPI allocations */
4763 vcpi
= kmemdup(pos
, sizeof(*vcpi
), GFP_KERNEL
);
4767 drm_dp_mst_get_port_malloc(vcpi
->port
);
4768 list_add(&vcpi
->next
, &state
->vcpis
);
4771 return &state
->base
;
4774 list_for_each_entry_safe(pos
, vcpi
, &state
->vcpis
, next
) {
4775 drm_dp_mst_put_port_malloc(pos
->port
);
4783 static void drm_dp_mst_destroy_state(struct drm_private_obj
*obj
,
4784 struct drm_private_state
*state
)
4786 struct drm_dp_mst_topology_state
*mst_state
=
4787 to_dp_mst_topology_state(state
);
4788 struct drm_dp_vcpi_allocation
*pos
, *tmp
;
4790 list_for_each_entry_safe(pos
, tmp
, &mst_state
->vcpis
, next
) {
4791 /* We only keep references to ports with non-zero VCPIs */
4793 drm_dp_mst_put_port_malloc(pos
->port
);
4800 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port
*port
,
4801 struct drm_dp_mst_branch
*branch
)
4803 while (port
->parent
) {
4804 if (port
->parent
== branch
)
4807 if (port
->parent
->port_parent
)
4808 port
= port
->parent
->port_parent
;
4816 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port
*port
,
4817 struct drm_dp_mst_topology_state
*state
);
4820 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch
*mstb
,
4821 struct drm_dp_mst_topology_state
*state
)
4823 struct drm_dp_vcpi_allocation
*vcpi
;
4824 struct drm_dp_mst_port
*port
;
4825 int pbn_used
= 0, ret
;
4828 /* Check that we have at least one port in our state that's downstream
4829 * of this branch, otherwise we can skip this branch
4831 list_for_each_entry(vcpi
, &state
->vcpis
, next
) {
4833 !drm_dp_mst_port_downstream_of_branch(vcpi
->port
, mstb
))
4842 if (mstb
->port_parent
)
4843 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
4844 mstb
->port_parent
->parent
, mstb
->port_parent
,
4847 DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n",
4850 list_for_each_entry(port
, &mstb
->ports
, next
) {
4851 ret
= drm_dp_mst_atomic_check_port_bw_limit(port
, state
);
4862 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port
*port
,
4863 struct drm_dp_mst_topology_state
*state
)
4865 struct drm_dp_vcpi_allocation
*vcpi
;
4868 if (port
->pdt
== DP_PEER_DEVICE_NONE
)
4871 if (drm_dp_mst_is_end_device(port
->pdt
, port
->mcs
)) {
4874 list_for_each_entry(vcpi
, &state
->vcpis
, next
) {
4875 if (vcpi
->port
!= port
)
4886 /* This should never happen, as it means we tried to
4887 * set a mode before querying the full_pbn
4889 if (WARN_ON(!port
->full_pbn
))
4892 pbn_used
= vcpi
->pbn
;
4894 pbn_used
= drm_dp_mst_atomic_check_mstb_bw_limit(port
->mstb
,
4900 if (pbn_used
> port
->full_pbn
) {
4901 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
4902 port
->parent
, port
, pbn_used
,
4907 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
4908 port
->parent
, port
, pbn_used
, port
->full_pbn
);
4914 drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr
*mgr
,
4915 struct drm_dp_mst_topology_state
*mst_state
)
4917 struct drm_dp_vcpi_allocation
*vcpi
;
4918 int avail_slots
= 63, payload_count
= 0;
4920 list_for_each_entry(vcpi
, &mst_state
->vcpis
, next
) {
4921 /* Releasing VCPI is always OK-even if the port is gone */
4923 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
4928 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
4929 vcpi
->port
, vcpi
->vcpi
);
4931 avail_slots
-= vcpi
->vcpi
;
4932 if (avail_slots
< 0) {
4933 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
4934 vcpi
->port
, mst_state
,
4935 avail_slots
+ vcpi
->vcpi
);
4939 if (++payload_count
> mgr
->max_payloads
) {
4940 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
4941 mgr
, mst_state
, mgr
->max_payloads
);
4945 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
4946 mgr
, mst_state
, avail_slots
,
4953 * drm_dp_mst_add_affected_dsc_crtcs
4954 * @state: Pointer to the new struct drm_dp_mst_topology_state
4955 * @mgr: MST topology manager
4957 * Whenever there is a change in mst topology
4958 * DSC configuration would have to be recalculated
4959 * therefore we need to trigger modeset on all affected
4960 * CRTCs in that topology
4963 * drm_dp_mst_atomic_enable_dsc()
4965 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state
*state
, struct drm_dp_mst_topology_mgr
*mgr
)
4967 struct drm_dp_mst_topology_state
*mst_state
;
4968 struct drm_dp_vcpi_allocation
*pos
;
4969 struct drm_connector
*connector
;
4970 struct drm_connector_state
*conn_state
;
4971 struct drm_crtc
*crtc
;
4972 struct drm_crtc_state
*crtc_state
;
4974 mst_state
= drm_atomic_get_mst_topology_state(state
, mgr
);
4976 if (IS_ERR(mst_state
))
4979 list_for_each_entry(pos
, &mst_state
->vcpis
, next
) {
4981 connector
= pos
->port
->connector
;
4986 conn_state
= drm_atomic_get_connector_state(state
, connector
);
4988 if (IS_ERR(conn_state
))
4989 return PTR_ERR(conn_state
);
4991 crtc
= conn_state
->crtc
;
4996 if (!drm_dp_mst_dsc_aux_for_port(pos
->port
))
4999 crtc_state
= drm_atomic_get_crtc_state(mst_state
->base
.state
, crtc
);
5001 if (IS_ERR(crtc_state
))
5002 return PTR_ERR(crtc_state
);
5004 DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5007 crtc_state
->mode_changed
= true;
5011 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs
);
5014 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5015 * @state: Pointer to the new drm_atomic_state
5016 * @port: Pointer to the affected MST Port
5017 * @pbn: Newly recalculated bw required for link with DSC enabled
5018 * @pbn_div: Divider to calculate correct number of pbn per slot
5019 * @enable: Boolean flag to enable or disable DSC on the port
5021 * This function enables DSC on the given Port
5022 * by recalculating its vcpi from pbn provided
5023 * and sets dsc_enable flag to keep track of which
5024 * ports have DSC enabled
5027 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state
*state
,
5028 struct drm_dp_mst_port
*port
,
5029 int pbn
, int pbn_div
,
5032 struct drm_dp_mst_topology_state
*mst_state
;
5033 struct drm_dp_vcpi_allocation
*pos
;
5037 mst_state
= drm_atomic_get_mst_topology_state(state
, port
->mgr
);
5039 if (IS_ERR(mst_state
))
5040 return PTR_ERR(mst_state
);
5042 list_for_each_entry(pos
, &mst_state
->vcpis
, next
) {
5043 if (pos
->port
== port
) {
5050 DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5055 if (pos
->dsc_enabled
== enable
) {
5056 DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5057 port
, enable
, pos
->vcpi
);
5062 vcpi
= drm_dp_atomic_find_vcpi_slots(state
, port
->mgr
, port
, pbn
, pbn_div
);
5063 DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5069 pos
->dsc_enabled
= enable
;
5073 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc
);
5075 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5076 * atomic update is valid
5077 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5079 * Checks the given topology state for an atomic update to ensure that it's
5080 * valid. This includes checking whether there's enough bandwidth to support
5081 * the new VCPI allocations in the atomic update.
5083 * Any atomic drivers supporting DP MST must make sure to call this after
5084 * checking the rest of their state in their
5085 * &drm_mode_config_funcs.atomic_check() callback.
5088 * drm_dp_atomic_find_vcpi_slots()
5089 * drm_dp_atomic_release_vcpi_slots()
5093 * 0 if the new state is valid, negative error code otherwise.
5095 int drm_dp_mst_atomic_check(struct drm_atomic_state
*state
)
5097 struct drm_dp_mst_topology_mgr
*mgr
;
5098 struct drm_dp_mst_topology_state
*mst_state
;
5101 for_each_new_mst_mgr_in_state(state
, mgr
, mst_state
, i
) {
5102 if (!mgr
->mst_state
)
5105 ret
= drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr
, mst_state
);
5109 mutex_lock(&mgr
->lock
);
5110 ret
= drm_dp_mst_atomic_check_mstb_bw_limit(mgr
->mst_primary
,
5112 mutex_unlock(&mgr
->lock
);
5121 EXPORT_SYMBOL(drm_dp_mst_atomic_check
);
5123 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs
= {
5124 .atomic_duplicate_state
= drm_dp_mst_duplicate_state
,
5125 .atomic_destroy_state
= drm_dp_mst_destroy_state
,
5127 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs
);
5130 * drm_atomic_get_mst_topology_state: get MST topology state
5132 * @state: global atomic state
5133 * @mgr: MST topology manager, also the private object in this case
5135 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5136 * state vtable so that the private object state returned is that of a MST
5137 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5138 * to care of the locking, so warn if don't hold the connection_mutex.
5142 * The MST topology state or error pointer.
5144 struct drm_dp_mst_topology_state
*drm_atomic_get_mst_topology_state(struct drm_atomic_state
*state
,
5145 struct drm_dp_mst_topology_mgr
*mgr
)
5147 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state
, &mgr
->base
));
5149 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state
);
5152 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5153 * @mgr: manager struct to initialise
5154 * @dev: device providing this structure - for i2c addition.
5155 * @aux: DP helper aux channel to talk to this device
5156 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5157 * @max_payloads: maximum number of payloads this GPU can source
5158 * @conn_base_id: the connector object ID the MST device is connected to.
5160 * Return 0 for success, or negative error code on failure
5162 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr
*mgr
,
5163 struct drm_device
*dev
, struct drm_dp_aux
*aux
,
5164 int max_dpcd_transaction_bytes
,
5165 int max_payloads
, int conn_base_id
)
5167 struct drm_dp_mst_topology_state
*mst_state
;
5169 mutex_init(&mgr
->lock
);
5170 mutex_init(&mgr
->qlock
);
5171 mutex_init(&mgr
->payload_lock
);
5172 mutex_init(&mgr
->delayed_destroy_lock
);
5173 mutex_init(&mgr
->up_req_lock
);
5174 mutex_init(&mgr
->probe_lock
);
5175 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5176 mutex_init(&mgr
->topology_ref_history_lock
);
5178 INIT_LIST_HEAD(&mgr
->tx_msg_downq
);
5179 INIT_LIST_HEAD(&mgr
->destroy_port_list
);
5180 INIT_LIST_HEAD(&mgr
->destroy_branch_device_list
);
5181 INIT_LIST_HEAD(&mgr
->up_req_list
);
5182 INIT_WORK(&mgr
->work
, drm_dp_mst_link_probe_work
);
5183 INIT_WORK(&mgr
->tx_work
, drm_dp_tx_work
);
5184 INIT_WORK(&mgr
->delayed_destroy_work
, drm_dp_delayed_destroy_work
);
5185 INIT_WORK(&mgr
->up_req_work
, drm_dp_mst_up_req_work
);
5186 init_waitqueue_head(&mgr
->tx_waitq
);
5189 mgr
->max_dpcd_transaction_bytes
= max_dpcd_transaction_bytes
;
5190 mgr
->max_payloads
= max_payloads
;
5191 mgr
->conn_base_id
= conn_base_id
;
5192 if (max_payloads
+ 1 > sizeof(mgr
->payload_mask
) * 8 ||
5193 max_payloads
+ 1 > sizeof(mgr
->vcpi_mask
) * 8)
5195 mgr
->payloads
= kcalloc(max_payloads
, sizeof(struct drm_dp_payload
), GFP_KERNEL
);
5198 mgr
->proposed_vcpis
= kcalloc(max_payloads
, sizeof(struct drm_dp_vcpi
*), GFP_KERNEL
);
5199 if (!mgr
->proposed_vcpis
)
5201 set_bit(0, &mgr
->payload_mask
);
5203 mst_state
= kzalloc(sizeof(*mst_state
), GFP_KERNEL
);
5204 if (mst_state
== NULL
)
5207 mst_state
->mgr
= mgr
;
5208 INIT_LIST_HEAD(&mst_state
->vcpis
);
5210 drm_atomic_private_obj_init(dev
, &mgr
->base
,
5212 &drm_dp_mst_topology_state_funcs
);
5216 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init
);
5219 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5220 * @mgr: manager to destroy
5222 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr
*mgr
)
5224 drm_dp_mst_topology_mgr_set_mst(mgr
, false);
5225 flush_work(&mgr
->work
);
5226 cancel_work_sync(&mgr
->delayed_destroy_work
);
5227 mutex_lock(&mgr
->payload_lock
);
5228 kfree(mgr
->payloads
);
5229 mgr
->payloads
= NULL
;
5230 kfree(mgr
->proposed_vcpis
);
5231 mgr
->proposed_vcpis
= NULL
;
5232 mutex_unlock(&mgr
->payload_lock
);
5235 drm_atomic_private_obj_fini(&mgr
->base
);
5238 mutex_destroy(&mgr
->delayed_destroy_lock
);
5239 mutex_destroy(&mgr
->payload_lock
);
5240 mutex_destroy(&mgr
->qlock
);
5241 mutex_destroy(&mgr
->lock
);
5242 mutex_destroy(&mgr
->up_req_lock
);
5243 mutex_destroy(&mgr
->probe_lock
);
5244 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5245 mutex_destroy(&mgr
->topology_ref_history_lock
);
5248 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy
);
5250 static bool remote_i2c_read_ok(const struct i2c_msg msgs
[], int num
)
5254 if (num
- 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS
)
5257 for (i
= 0; i
< num
- 1; i
++) {
5258 if (msgs
[i
].flags
& I2C_M_RD
||
5263 return msgs
[num
- 1].flags
& I2C_M_RD
&&
5264 msgs
[num
- 1].len
<= 0xff;
5268 static int drm_dp_mst_i2c_xfer(struct i2c_adapter
*adapter
, struct i2c_msg
*msgs
,
5271 struct drm_dp_aux
*aux
= adapter
->algo_data
;
5272 struct drm_dp_mst_port
*port
= container_of(aux
, struct drm_dp_mst_port
, aux
);
5273 struct drm_dp_mst_branch
*mstb
;
5274 struct drm_dp_mst_topology_mgr
*mgr
= port
->mgr
;
5276 struct drm_dp_sideband_msg_req_body msg
;
5277 struct drm_dp_sideband_msg_tx
*txmsg
= NULL
;
5280 mstb
= drm_dp_mst_topology_get_mstb_validated(mgr
, port
->parent
);
5284 if (!remote_i2c_read_ok(msgs
, num
)) {
5285 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
5290 memset(&msg
, 0, sizeof(msg
));
5291 msg
.req_type
= DP_REMOTE_I2C_READ
;
5292 msg
.u
.i2c_read
.num_transactions
= num
- 1;
5293 msg
.u
.i2c_read
.port_number
= port
->port_num
;
5294 for (i
= 0; i
< num
- 1; i
++) {
5295 msg
.u
.i2c_read
.transactions
[i
].i2c_dev_id
= msgs
[i
].addr
;
5296 msg
.u
.i2c_read
.transactions
[i
].num_bytes
= msgs
[i
].len
;
5297 msg
.u
.i2c_read
.transactions
[i
].bytes
= msgs
[i
].buf
;
5298 msg
.u
.i2c_read
.transactions
[i
].no_stop_bit
= !(msgs
[i
].flags
& I2C_M_STOP
);
5300 msg
.u
.i2c_read
.read_i2c_device_id
= msgs
[num
- 1].addr
;
5301 msg
.u
.i2c_read
.num_bytes_read
= msgs
[num
- 1].len
;
5303 txmsg
= kzalloc(sizeof(*txmsg
), GFP_KERNEL
);
5310 drm_dp_encode_sideband_req(&msg
, txmsg
);
5312 drm_dp_queue_down_tx(mgr
, txmsg
);
5314 ret
= drm_dp_mst_wait_tx_reply(mstb
, txmsg
);
5317 if (txmsg
->reply
.reply_type
== DP_SIDEBAND_REPLY_NAK
) {
5321 if (txmsg
->reply
.u
.remote_i2c_read_ack
.num_bytes
!= msgs
[num
- 1].len
) {
5325 memcpy(msgs
[num
- 1].buf
, txmsg
->reply
.u
.remote_i2c_read_ack
.bytes
, msgs
[num
- 1].len
);
5330 drm_dp_mst_topology_put_mstb(mstb
);
5334 static u32
drm_dp_mst_i2c_functionality(struct i2c_adapter
*adapter
)
5336 return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_EMUL
|
5337 I2C_FUNC_SMBUS_READ_BLOCK_DATA
|
5338 I2C_FUNC_SMBUS_BLOCK_PROC_CALL
|
5339 I2C_FUNC_10BIT_ADDR
;
5342 static const struct i2c_algorithm drm_dp_mst_i2c_algo
= {
5343 .functionality
= drm_dp_mst_i2c_functionality
,
5344 .master_xfer
= drm_dp_mst_i2c_xfer
,
5348 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5349 * @aux: DisplayPort AUX channel
5351 * Returns 0 on success or a negative error code on failure.
5353 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux
*aux
)
5355 aux
->ddc
.algo
= &drm_dp_mst_i2c_algo
;
5356 aux
->ddc
.algo_data
= aux
;
5357 aux
->ddc
.retries
= 3;
5359 aux
->ddc
.class = I2C_CLASS_DDC
;
5360 aux
->ddc
.owner
= THIS_MODULE
;
5361 aux
->ddc
.dev
.parent
= aux
->dev
;
5362 aux
->ddc
.dev
.of_node
= aux
->dev
->of_node
;
5364 strlcpy(aux
->ddc
.name
, aux
->name
? aux
->name
: dev_name(aux
->dev
),
5365 sizeof(aux
->ddc
.name
));
5367 return i2c_add_adapter(&aux
->ddc
);
5371 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5372 * @aux: DisplayPort AUX channel
5374 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux
*aux
)
5376 i2c_del_adapter(&aux
->ddc
);
5380 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5381 * @port: The port to check
5383 * A single physical MST hub object can be represented in the topology
5384 * by multiple branches, with virtual ports between those branches.
5386 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5387 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5388 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5390 * May acquire mgr->lock
5393 * true if the port is a virtual DP peer device, false otherwise
5395 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port
*port
)
5397 struct drm_dp_mst_port
*downstream_port
;
5399 if (!port
|| port
->dpcd_rev
< DP_DPCD_REV_14
)
5402 /* Virtual DP Sink (Internal Display Panel) */
5403 if (port
->port_num
>= 8)
5406 /* DP-to-HDMI Protocol Converter */
5407 if (port
->pdt
== DP_PEER_DEVICE_DP_LEGACY_CONV
&&
5413 mutex_lock(&port
->mgr
->lock
);
5414 if (port
->pdt
== DP_PEER_DEVICE_MST_BRANCHING
&&
5416 port
->mstb
->num_ports
== 2) {
5417 list_for_each_entry(downstream_port
, &port
->mstb
->ports
, next
) {
5418 if (downstream_port
->pdt
== DP_PEER_DEVICE_SST_SINK
&&
5419 !downstream_port
->input
) {
5420 mutex_unlock(&port
->mgr
->lock
);
5425 mutex_unlock(&port
->mgr
->lock
);
5431 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5432 * @port: The port to check. A leaf of the MST tree with an attached display.
5434 * Depending on the situation, DSC may be enabled via the endpoint aux,
5435 * the immediately upstream aux, or the connector's physical aux.
5437 * This is both the correct aux to read DSC_CAPABILITY and the
5438 * correct aux to write DSC_ENABLED.
5440 * This operation can be expensive (up to four aux reads), so
5441 * the caller should cache the return.
5444 * NULL if DSC cannot be enabled on this port, otherwise the aux device
5446 struct drm_dp_aux
*drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port
*port
)
5448 struct drm_dp_mst_port
*immediate_upstream_port
;
5449 struct drm_dp_mst_port
*fec_port
;
5450 struct drm_dp_desc desc
= { };
5457 if (port
->parent
->port_parent
)
5458 immediate_upstream_port
= port
->parent
->port_parent
;
5460 immediate_upstream_port
= NULL
;
5462 fec_port
= immediate_upstream_port
;
5465 * Each physical link (i.e. not a virtual port) between the
5466 * output and the primary device must support FEC
5468 if (!drm_dp_mst_is_virtual_dpcd(fec_port
) &&
5469 !fec_port
->fec_capable
)
5472 fec_port
= fec_port
->parent
->port_parent
;
5475 /* DP-to-DP peer device */
5476 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port
)) {
5479 if (drm_dp_dpcd_read(&port
->aux
,
5480 DP_DSC_SUPPORT
, &endpoint_dsc
, 1) != 1)
5482 if (drm_dp_dpcd_read(&port
->aux
,
5483 DP_FEC_CAPABILITY
, &endpoint_fec
, 1) != 1)
5485 if (drm_dp_dpcd_read(&immediate_upstream_port
->aux
,
5486 DP_DSC_SUPPORT
, &upstream_dsc
, 1) != 1)
5489 /* Enpoint decompression with DP-to-DP peer device */
5490 if ((endpoint_dsc
& DP_DSC_DECOMPRESSION_IS_SUPPORTED
) &&
5491 (endpoint_fec
& DP_FEC_CAPABLE
) &&
5492 (upstream_dsc
& 0x2) /* DSC passthrough */)
5495 /* Virtual DPCD decompression with DP-to-DP peer device */
5496 return &immediate_upstream_port
->aux
;
5499 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5500 if (drm_dp_mst_is_virtual_dpcd(port
))
5505 * Applies to ports for which:
5506 * - Physical aux has Synaptics OUI
5507 * - DPv1.4 or higher
5508 * - Port is on primary branch device
5509 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5511 if (drm_dp_read_desc(port
->mgr
->aux
, &desc
, true))
5514 if (drm_dp_has_quirk(&desc
, 0,
5515 DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD
) &&
5516 port
->mgr
->dpcd
[DP_DPCD_REV
] >= DP_DPCD_REV_14
&&
5517 port
->parent
== port
->mgr
->mst_primary
) {
5520 if (drm_dp_dpcd_read(&port
->aux
, DP_DOWNSTREAMPORT_PRESENT
,
5521 &downstreamport
, 1) < 0)
5524 if ((downstreamport
& DP_DWN_STRM_PORT_PRESENT
) &&
5525 ((downstreamport
& DP_DWN_STRM_PORT_TYPE_MASK
)
5526 != DP_DWN_STRM_PORT_TYPE_ANALOG
))
5527 return port
->mgr
->aux
;
5531 * The check below verifies if the MST sink
5532 * connected to the GPU is capable of DSC -
5533 * therefore the endpoint needs to be
5534 * both DSC and FEC capable.
5536 if (drm_dp_dpcd_read(&port
->aux
,
5537 DP_DSC_SUPPORT
, &endpoint_dsc
, 1) != 1)
5539 if (drm_dp_dpcd_read(&port
->aux
,
5540 DP_FEC_CAPABILITY
, &endpoint_fec
, 1) != 1)
5542 if ((endpoint_dsc
& DP_DSC_DECOMPRESSION_IS_SUPPORTED
) &&
5543 (endpoint_fec
& DP_FEC_CAPABLE
))
5548 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port
);