2 * drm_irq.c IRQ and vblank support
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
36 #include "drm_trace.h"
37 #include "drm_internal.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Access macro for slots in vblank timestamp ringbuffer. */
46 #define vblanktimestamp(dev, pipe, count) \
47 ((dev)->vblank[pipe].time[(count) % DRM_VBLANKTIME_RBSIZE])
49 /* Retry timestamp calculation up to 3 times to satisfy
50 * drm_timestamp_precision before giving up.
52 #define DRM_TIMESTAMP_MAXRETRIES 3
54 /* Threshold in nanoseconds for detection of redundant
55 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
57 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
60 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
61 struct timeval
*tvblank
, unsigned flags
);
63 static unsigned int drm_timestamp_precision
= 20; /* Default to 20 usecs. */
66 * Default to use monotonic timestamps for wait-for-vblank and page-flip
69 unsigned int drm_timestamp_monotonic
= 1;
71 static int drm_vblank_offdelay
= 5000; /* Default to 5000 msecs. */
73 module_param_named(vblankoffdelay
, drm_vblank_offdelay
, int, 0600);
74 module_param_named(timestamp_precision_usec
, drm_timestamp_precision
, int, 0600);
75 module_param_named(timestamp_monotonic
, drm_timestamp_monotonic
, int, 0600);
76 MODULE_PARM_DESC(vblankoffdelay
, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
77 MODULE_PARM_DESC(timestamp_precision_usec
, "Max. error on timestamps [usecs]");
78 MODULE_PARM_DESC(timestamp_monotonic
, "Use monotonic timestamps");
80 static void store_vblank(struct drm_device
*dev
, unsigned int pipe
,
82 struct timeval
*t_vblank
, u32 last
)
84 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
87 assert_spin_locked(&dev
->vblank_time_lock
);
91 /* All writers hold the spinlock, but readers are serialized by
92 * the latching of vblank->count below.
94 tslot
= vblank
->count
+ vblank_count_inc
;
95 vblanktimestamp(dev
, pipe
, tslot
) = *t_vblank
;
98 * vblank timestamp updates are protected on the write side with
99 * vblank_time_lock, but on the read side done locklessly using a
100 * sequence-lock on the vblank counter. Ensure correct ordering using
101 * memory barrriers. We need the barrier both before and also after the
102 * counter update to synchronize with the next timestamp write.
103 * The read-side barriers for this are in drm_vblank_count_and_time.
106 vblank
->count
+= vblank_count_inc
;
111 * drm_reset_vblank_timestamp - reset the last timestamp to the last vblank
113 * @pipe: index of CRTC for which to reset the timestamp
115 * Reset the stored timestamp for the current vblank count to correspond
116 * to the last vblank occurred.
118 * Only to be called from drm_vblank_on().
120 * Note: caller must hold dev->vbl_lock since this reads & writes
121 * device vblank fields.
123 static void drm_reset_vblank_timestamp(struct drm_device
*dev
, unsigned int pipe
)
127 struct timeval t_vblank
;
128 int count
= DRM_TIMESTAMP_MAXRETRIES
;
130 spin_lock(&dev
->vblank_time_lock
);
133 * sample the current counter to avoid random jumps
134 * when drm_vblank_enable() applies the diff
137 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
138 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, 0);
139 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
142 * Only reinitialize corresponding vblank timestamp if high-precision query
143 * available and didn't fail. Otherwise reinitialize delayed at next vblank
144 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
147 t_vblank
= (struct timeval
) {0, 0};
150 * +1 to make sure user will never see the same
151 * vblank counter value before and after a modeset
153 store_vblank(dev
, pipe
, 1, &t_vblank
, cur_vblank
);
155 spin_unlock(&dev
->vblank_time_lock
);
159 * drm_update_vblank_count - update the master vblank counter
161 * @pipe: counter to update
163 * Call back into the driver to update the appropriate vblank counter
164 * (specified by @pipe). Deal with wraparound, if it occurred, and
165 * update the last read value so we can deal with wraparound on the next
168 * Only necessary when going from off->on, to account for frames we
169 * didn't get an interrupt for.
171 * Note: caller must hold dev->vbl_lock since this reads & writes
172 * device vblank fields.
174 static void drm_update_vblank_count(struct drm_device
*dev
, unsigned int pipe
,
177 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
178 u32 cur_vblank
, diff
;
180 struct timeval t_vblank
;
181 int count
= DRM_TIMESTAMP_MAXRETRIES
;
182 int framedur_ns
= vblank
->framedur_ns
;
185 * Interrupts were disabled prior to this call, so deal with counter
187 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
188 * here if the register is small or we had vblank interrupts off for
191 * We repeat the hardware vblank counter & timestamp query until
192 * we get consistent results. This to prevent races between gpu
193 * updating its hardware counter while we are retrieving the
194 * corresponding vblank timestamp.
197 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
198 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, flags
);
199 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
201 if (dev
->max_vblank_count
!= 0) {
202 /* trust the hw counter when it's around */
203 diff
= (cur_vblank
- vblank
->last
) & dev
->max_vblank_count
;
204 } else if (rc
&& framedur_ns
) {
205 const struct timeval
*t_old
;
208 t_old
= &vblanktimestamp(dev
, pipe
, vblank
->count
);
209 diff_ns
= timeval_to_ns(&t_vblank
) - timeval_to_ns(t_old
);
212 * Figure out how many vblanks we've missed based
213 * on the difference in the timestamps and the
214 * frame/field duration.
216 diff
= DIV_ROUND_CLOSEST_ULL(diff_ns
, framedur_ns
);
218 if (diff
== 0 && flags
& DRM_CALLED_FROM_VBLIRQ
)
219 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
220 " diff_ns = %lld, framedur_ns = %d)\n",
221 pipe
, (long long) diff_ns
, framedur_ns
);
223 /* some kind of default for drivers w/o accurate vbl timestamping */
224 diff
= (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0;
228 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
229 * interval? If so then vblank irqs keep running and it will likely
230 * happen that the hardware vblank counter is not trustworthy as it
231 * might reset at some point in that interval and vblank timestamps
232 * are not trustworthy either in that interval. Iow. this can result
233 * in a bogus diff >> 1 which must be avoided as it would cause
234 * random large forward jumps of the software vblank counter.
236 if (diff
> 1 && (vblank
->inmodeset
& 0x2)) {
237 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
238 " due to pre-modeset.\n", pipe
, diff
);
243 * FIMXE: Need to replace this hack with proper seqlocks.
245 * Restrict the bump of the software vblank counter to a safe maximum
246 * value of +1 whenever there is the possibility that concurrent readers
247 * of vblank timestamps could be active at the moment, as the current
248 * implementation of the timestamp caching and updating is not safe
249 * against concurrent readers for calls to store_vblank() with a bump
250 * of anything but +1. A bump != 1 would very likely return corrupted
251 * timestamps to userspace, because the same slot in the cache could
252 * be concurrently written by store_vblank() and read by one of those
253 * readers without the read-retry logic detecting the collision.
255 * Concurrent readers can exist when we are called from the
256 * drm_vblank_off() or drm_vblank_on() functions and other non-vblank-
257 * irq callers. However, all those calls to us are happening with the
258 * vbl_lock locked to prevent drm_vblank_get(), so the vblank refcount
259 * can't increase while we are executing. Therefore a zero refcount at
260 * this point is safe for arbitrary counter bumps if we are called
261 * outside vblank irq, a non-zero count is not 100% safe. Unfortunately
262 * we must also accept a refcount of 1, as whenever we are called from
263 * drm_vblank_get() -> drm_vblank_enable() the refcount will be 1 and
264 * we must let that one pass through in order to not lose vblank counts
265 * during vblank irq off - which would completely defeat the whole
266 * point of this routine.
268 * Whenever we are called from vblank irq, we have to assume concurrent
269 * readers exist or can show up any time during our execution, even if
270 * the refcount is currently zero, as vblank irqs are usually only
271 * enabled due to the presence of readers, and because when we are called
272 * from vblank irq we can't hold the vbl_lock to protect us from sudden
273 * bumps in vblank refcount. Therefore also restrict bumps to +1 when
274 * called from vblank irq.
276 if ((diff
> 1) && (atomic_read(&vblank
->refcount
) > 1 ||
277 (flags
& DRM_CALLED_FROM_VBLIRQ
))) {
278 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u "
279 "refcount %u, vblirq %u\n", pipe
, diff
,
280 atomic_read(&vblank
->refcount
),
281 (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0);
285 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
286 " current=%u, diff=%u, hw=%u hw_last=%u\n",
287 pipe
, vblank
->count
, diff
, cur_vblank
, vblank
->last
);
290 WARN_ON_ONCE(cur_vblank
!= vblank
->last
);
295 * Only reinitialize corresponding vblank timestamp if high-precision query
296 * available and didn't fail, or we were called from the vblank interrupt.
297 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
298 * for now, to mark the vblanktimestamp as invalid.
300 if (!rc
&& (flags
& DRM_CALLED_FROM_VBLIRQ
) == 0)
301 t_vblank
= (struct timeval
) {0, 0};
303 store_vblank(dev
, pipe
, diff
, &t_vblank
, cur_vblank
);
307 * Disable vblank irq's on crtc, make sure that last vblank count
308 * of hardware and corresponding consistent software vblank counter
309 * are preserved, even if there are any spurious vblank irq's after
312 static void vblank_disable_and_save(struct drm_device
*dev
, unsigned int pipe
)
314 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
315 unsigned long irqflags
;
317 /* Prevent vblank irq processing while disabling vblank irqs,
318 * so no updates of timestamps or count can happen after we've
319 * disabled. Needed to prevent races in case of delayed irq's.
321 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
324 * Only disable vblank interrupts if they're enabled. This avoids
325 * calling the ->disable_vblank() operation in atomic context with the
326 * hardware potentially runtime suspended.
328 if (vblank
->enabled
) {
329 dev
->driver
->disable_vblank(dev
, pipe
);
330 vblank
->enabled
= false;
334 * Always update the count and timestamp to maintain the
335 * appearance that the counter has been ticking all along until
336 * this time. This makes the count account for the entire time
337 * between drm_vblank_on() and drm_vblank_off().
339 drm_update_vblank_count(dev
, pipe
, 0);
341 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
344 static void vblank_disable_fn(unsigned long arg
)
346 struct drm_vblank_crtc
*vblank
= (void *)arg
;
347 struct drm_device
*dev
= vblank
->dev
;
348 unsigned int pipe
= vblank
->pipe
;
349 unsigned long irqflags
;
351 if (!dev
->vblank_disable_allowed
)
354 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
355 if (atomic_read(&vblank
->refcount
) == 0 && vblank
->enabled
) {
356 DRM_DEBUG("disabling vblank on crtc %u\n", pipe
);
357 vblank_disable_and_save(dev
, pipe
);
359 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
363 * drm_vblank_cleanup - cleanup vblank support
366 * This function cleans up any resources allocated in drm_vblank_init.
368 void drm_vblank_cleanup(struct drm_device
*dev
)
372 /* Bail if the driver didn't call drm_vblank_init() */
373 if (dev
->num_crtcs
== 0)
376 for (pipe
= 0; pipe
< dev
->num_crtcs
; pipe
++) {
377 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
379 WARN_ON(vblank
->enabled
&&
380 drm_core_check_feature(dev
, DRIVER_MODESET
));
382 del_timer_sync(&vblank
->disable_timer
);
389 EXPORT_SYMBOL(drm_vblank_cleanup
);
392 * drm_vblank_init - initialize vblank support
394 * @num_crtcs: number of CRTCs supported by @dev
396 * This function initializes vblank support for @num_crtcs display pipelines.
399 * Zero on success or a negative error code on failure.
401 int drm_vblank_init(struct drm_device
*dev
, unsigned int num_crtcs
)
406 spin_lock_init(&dev
->vbl_lock
);
407 spin_lock_init(&dev
->vblank_time_lock
);
409 dev
->num_crtcs
= num_crtcs
;
411 dev
->vblank
= kcalloc(num_crtcs
, sizeof(*dev
->vblank
), GFP_KERNEL
);
415 for (i
= 0; i
< num_crtcs
; i
++) {
416 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
420 init_waitqueue_head(&vblank
->queue
);
421 setup_timer(&vblank
->disable_timer
, vblank_disable_fn
,
422 (unsigned long)vblank
);
425 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
427 /* Driver specific high-precision vblank timestamping supported? */
428 if (dev
->driver
->get_vblank_timestamp
)
429 DRM_INFO("Driver supports precise vblank timestamp query.\n");
431 DRM_INFO("No driver support for vblank timestamp query.\n");
433 /* Must have precise timestamping for reliable vblank instant disable */
434 if (dev
->vblank_disable_immediate
&& !dev
->driver
->get_vblank_timestamp
) {
435 dev
->vblank_disable_immediate
= false;
436 DRM_INFO("Setting vblank_disable_immediate to false because "
437 "get_vblank_timestamp == NULL\n");
440 dev
->vblank_disable_allowed
= false;
448 EXPORT_SYMBOL(drm_vblank_init
);
450 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
452 struct drm_device
*dev
= cookie
;
454 if (dev
->driver
->vgaarb_irq
) {
455 dev
->driver
->vgaarb_irq(dev
, state
);
459 if (!dev
->irq_enabled
)
463 if (dev
->driver
->irq_uninstall
)
464 dev
->driver
->irq_uninstall(dev
);
466 if (dev
->driver
->irq_preinstall
)
467 dev
->driver
->irq_preinstall(dev
);
468 if (dev
->driver
->irq_postinstall
)
469 dev
->driver
->irq_postinstall(dev
);
474 * drm_irq_install - install IRQ handler
476 * @irq: IRQ number to install the handler for
478 * Initializes the IRQ related data. Installs the handler, calling the driver
479 * irq_preinstall() and irq_postinstall() functions before and after the
482 * This is the simplified helper interface provided for drivers with no special
483 * needs. Drivers which need to install interrupt handlers for multiple
484 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
485 * that vblank interrupts are available.
488 * Zero on success or a negative error code on failure.
490 int drm_irq_install(struct drm_device
*dev
, int irq
)
493 unsigned long sh_flags
= 0;
495 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
501 /* Driver must have been initialized */
502 if (!dev
->dev_private
)
505 if (dev
->irq_enabled
)
507 dev
->irq_enabled
= true;
509 DRM_DEBUG("irq=%d\n", irq
);
511 /* Before installing handler */
512 if (dev
->driver
->irq_preinstall
)
513 dev
->driver
->irq_preinstall(dev
);
515 /* Install handler */
516 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
517 sh_flags
= IRQF_SHARED
;
519 ret
= request_irq(irq
, dev
->driver
->irq_handler
,
520 sh_flags
, dev
->driver
->name
, dev
);
523 dev
->irq_enabled
= false;
527 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
528 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
530 /* After installing handler */
531 if (dev
->driver
->irq_postinstall
)
532 ret
= dev
->driver
->irq_postinstall(dev
);
535 dev
->irq_enabled
= false;
536 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
537 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
545 EXPORT_SYMBOL(drm_irq_install
);
548 * drm_irq_uninstall - uninstall the IRQ handler
551 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
552 * This should only be called by drivers which used drm_irq_install() to set up
553 * their interrupt handler. Other drivers must only reset
554 * drm_device->irq_enabled to false.
556 * Note that for kernel modesetting drivers it is a bug if this function fails.
557 * The sanity checks are only to catch buggy user modesetting drivers which call
558 * the same function through an ioctl.
561 * Zero on success or a negative error code on failure.
563 int drm_irq_uninstall(struct drm_device
*dev
)
565 unsigned long irqflags
;
569 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
572 irq_enabled
= dev
->irq_enabled
;
573 dev
->irq_enabled
= false;
576 * Wake up any waiters so they don't hang. This is just to paper over
577 * isssues for UMS drivers which aren't in full control of their
578 * vblank/irq handling. KMS drivers must ensure that vblanks are all
579 * disabled when uninstalling the irq handler.
581 if (dev
->num_crtcs
) {
582 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
583 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
584 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
586 if (!vblank
->enabled
)
589 WARN_ON(drm_core_check_feature(dev
, DRIVER_MODESET
));
591 vblank_disable_and_save(dev
, i
);
592 wake_up(&vblank
->queue
);
594 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
600 DRM_DEBUG("irq=%d\n", dev
->irq
);
602 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
603 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
605 if (dev
->driver
->irq_uninstall
)
606 dev
->driver
->irq_uninstall(dev
);
608 free_irq(dev
->irq
, dev
);
612 EXPORT_SYMBOL(drm_irq_uninstall
);
617 * \param inode device inode.
618 * \param file_priv DRM file private.
619 * \param cmd command.
620 * \param arg user argument, pointing to a drm_control structure.
621 * \return zero on success or a negative number on failure.
623 * Calls irq_install() or irq_uninstall() according to \p arg.
625 int drm_control(struct drm_device
*dev
, void *data
,
626 struct drm_file
*file_priv
)
628 struct drm_control
*ctl
= data
;
631 /* if we haven't irq we fallback for compatibility reasons -
632 * this used to be a separate function in drm_dma.h
635 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
637 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
639 /* UMS was only ever support on pci devices. */
640 if (WARN_ON(!dev
->pdev
))
644 case DRM_INST_HANDLER
:
645 irq
= dev
->pdev
->irq
;
647 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
650 mutex_lock(&dev
->struct_mutex
);
651 ret
= drm_irq_install(dev
, irq
);
652 mutex_unlock(&dev
->struct_mutex
);
655 case DRM_UNINST_HANDLER
:
656 mutex_lock(&dev
->struct_mutex
);
657 ret
= drm_irq_uninstall(dev
);
658 mutex_unlock(&dev
->struct_mutex
);
667 * drm_calc_timestamping_constants - calculate vblank timestamp constants
668 * @crtc: drm_crtc whose timestamp constants should be updated.
669 * @mode: display mode containing the scanout timings
671 * Calculate and store various constants which are later
672 * needed by vblank and swap-completion timestamping, e.g,
673 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
674 * derived from CRTC's true scanout timing, so they take
675 * things like panel scaling or other adjustments into account.
677 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
,
678 const struct drm_display_mode
*mode
)
680 struct drm_device
*dev
= crtc
->dev
;
681 unsigned int pipe
= drm_crtc_index(crtc
);
682 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
683 int linedur_ns
= 0, framedur_ns
= 0;
684 int dotclock
= mode
->crtc_clock
;
689 if (WARN_ON(pipe
>= dev
->num_crtcs
))
692 /* Valid dotclock? */
694 int frame_size
= mode
->crtc_htotal
* mode
->crtc_vtotal
;
697 * Convert scanline length in pixels and video
698 * dot clock to line duration and frame duration
701 linedur_ns
= div_u64((u64
) mode
->crtc_htotal
* 1000000, dotclock
);
702 framedur_ns
= div_u64((u64
) frame_size
* 1000000, dotclock
);
705 * Fields of interlaced scanout modes are only half a frame duration.
707 if (mode
->flags
& DRM_MODE_FLAG_INTERLACE
)
710 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
713 vblank
->linedur_ns
= linedur_ns
;
714 vblank
->framedur_ns
= framedur_ns
;
716 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
717 crtc
->base
.id
, mode
->crtc_htotal
,
718 mode
->crtc_vtotal
, mode
->crtc_vdisplay
);
719 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
720 crtc
->base
.id
, dotclock
, framedur_ns
, linedur_ns
);
722 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
725 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
727 * @pipe: index of CRTC whose vblank timestamp to retrieve
728 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
729 * On return contains true maximum error of timestamp
730 * @vblank_time: Pointer to struct timeval which should receive the timestamp
731 * @flags: Flags to pass to driver:
733 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
734 * @mode: mode which defines the scanout timings
736 * Implements calculation of exact vblank timestamps from given drm_display_mode
737 * timings and current video scanout position of a CRTC. This can be called from
738 * within get_vblank_timestamp() implementation of a kms driver to implement the
739 * actual timestamping.
741 * Should return timestamps conforming to the OML_sync_control OpenML
742 * extension specification. The timestamp corresponds to the end of
743 * the vblank interval, aka start of scanout of topmost-leftmost display
744 * pixel in the following video frame.
746 * Requires support for optional dev->driver->get_scanout_position()
747 * in kms driver, plus a bit of setup code to provide a drm_display_mode
748 * that corresponds to the true scanout timing.
750 * The current implementation only handles standard video modes. It
751 * returns as no operation if a doublescan or interlaced video mode is
752 * active. Higher level code is expected to handle this.
755 * Negative value on error, failure or if not supported in current
758 * -EINVAL - Invalid CRTC.
759 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
760 * -ENOTSUPP - Function not supported in current display mode.
761 * -EIO - Failed, e.g., due to failed scanout position query.
763 * Returns or'ed positive status flags on success:
765 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
766 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
769 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
,
772 struct timeval
*vblank_time
,
774 const struct drm_display_mode
*mode
)
776 struct timeval tv_etime
;
777 ktime_t stime
, etime
;
778 unsigned int vbl_status
;
779 int ret
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
781 int delta_ns
, duration_ns
;
783 if (pipe
>= dev
->num_crtcs
) {
784 DRM_ERROR("Invalid crtc %u\n", pipe
);
788 /* Scanout position query not supported? Should not happen. */
789 if (!dev
->driver
->get_scanout_position
) {
790 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
794 /* If mode timing undefined, just return as no-op:
795 * Happens during initial modesetting of a crtc.
797 if (mode
->crtc_clock
== 0) {
798 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe
);
802 /* Get current scanout position with system timestamp.
803 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
804 * if single query takes longer than max_error nanoseconds.
806 * This guarantees a tight bound on maximum error if
807 * code gets preempted or delayed for some reason.
809 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
811 * Get vertical and horizontal scanout position vpos, hpos,
812 * and bounding timestamps stime, etime, pre/post query.
814 vbl_status
= dev
->driver
->get_scanout_position(dev
, pipe
, flags
,
819 /* Return as no-op if scanout query unsupported or failed. */
820 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
821 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
826 /* Compute uncertainty in timestamp of scanout position query. */
827 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
829 /* Accept result with < max_error nsecs timing uncertainty. */
830 if (duration_ns
<= *max_error
)
834 /* Noisy system timing? */
835 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
836 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
837 pipe
, duration_ns
/1000, *max_error
/1000, i
);
840 /* Return upper bound of timestamp precision error. */
841 *max_error
= duration_ns
;
843 /* Check if in vblank area:
844 * vpos is >=0 in video scanout area, but negative
845 * within vblank area, counting down the number of lines until
848 if (vbl_status
& DRM_SCANOUTPOS_IN_VBLANK
)
849 ret
|= DRM_VBLANKTIME_IN_VBLANK
;
851 /* Convert scanout position into elapsed time at raw_time query
852 * since start of scanout at first display scanline. delta_ns
853 * can be negative if start of scanout hasn't happened yet.
855 delta_ns
= div_s64(1000000LL * (vpos
* mode
->crtc_htotal
+ hpos
),
858 if (!drm_timestamp_monotonic
)
859 etime
= ktime_mono_to_real(etime
);
861 /* save this only for debugging purposes */
862 tv_etime
= ktime_to_timeval(etime
);
863 /* Subtract time delta from raw timestamp to get final
864 * vblank_time timestamp for end of vblank.
866 etime
= ktime_sub_ns(etime
, delta_ns
);
867 *vblank_time
= ktime_to_timeval(etime
);
869 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
870 pipe
, vbl_status
, hpos
, vpos
,
871 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
872 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
873 duration_ns
/1000, i
);
877 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
879 static struct timeval
get_drm_timestamp(void)
883 now
= drm_timestamp_monotonic
? ktime_get() : ktime_get_real();
884 return ktime_to_timeval(now
);
888 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
891 * @pipe: index of CRTC whose vblank timestamp to retrieve
892 * @tvblank: Pointer to target struct timeval which should receive the timestamp
893 * @flags: Flags to pass to driver:
895 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
897 * Fetches the system timestamp corresponding to the time of the most recent
898 * vblank interval on specified CRTC. May call into kms-driver to
899 * compute the timestamp with a high-precision GPU specific method.
901 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
902 * call, i.e., it isn't very precisely locked to the true vblank.
905 * True if timestamp is considered to be very precise, false otherwise.
908 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
909 struct timeval
*tvblank
, unsigned flags
)
913 /* Define requested maximum error on timestamps (nanoseconds). */
914 int max_error
= (int) drm_timestamp_precision
* 1000;
916 /* Query driver if possible and precision timestamping enabled. */
917 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
918 ret
= dev
->driver
->get_vblank_timestamp(dev
, pipe
, &max_error
,
924 /* GPU high precision timestamp query unsupported or failed.
925 * Return current monotonic/gettimeofday timestamp as best estimate.
927 *tvblank
= get_drm_timestamp();
933 * drm_vblank_count - retrieve "cooked" vblank counter value
935 * @pipe: index of CRTC for which to retrieve the counter
937 * Fetches the "cooked" vblank count value that represents the number of
938 * vblank events since the system was booted, including lost events due to
939 * modesetting activity.
941 * This is the legacy version of drm_crtc_vblank_count().
944 * The software vblank counter.
946 u32
drm_vblank_count(struct drm_device
*dev
, unsigned int pipe
)
948 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
950 if (WARN_ON(pipe
>= dev
->num_crtcs
))
953 return vblank
->count
;
955 EXPORT_SYMBOL(drm_vblank_count
);
958 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
959 * @crtc: which counter to retrieve
961 * Fetches the "cooked" vblank count value that represents the number of
962 * vblank events since the system was booted, including lost events due to
963 * modesetting activity.
965 * This is the native KMS version of drm_vblank_count().
968 * The software vblank counter.
970 u32
drm_crtc_vblank_count(struct drm_crtc
*crtc
)
972 return drm_vblank_count(crtc
->dev
, drm_crtc_index(crtc
));
974 EXPORT_SYMBOL(drm_crtc_vblank_count
);
977 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
978 * system timestamp corresponding to that vblank counter value.
980 * @pipe: index of CRTC whose counter to retrieve
981 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
983 * Fetches the "cooked" vblank count value that represents the number of
984 * vblank events since the system was booted, including lost events due to
985 * modesetting activity. Returns corresponding system timestamp of the time
986 * of the vblank interval that corresponds to the current vblank counter value.
988 * This is the legacy version of drm_crtc_vblank_count_and_time().
990 u32
drm_vblank_count_and_time(struct drm_device
*dev
, unsigned int pipe
,
991 struct timeval
*vblanktime
)
993 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
994 int count
= DRM_TIMESTAMP_MAXRETRIES
;
997 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1001 * Vblank timestamps are read lockless. To ensure consistency the vblank
1002 * counter is rechecked and ordering is ensured using memory barriers.
1003 * This works like a seqlock. The write-side barriers are in store_vblank.
1006 cur_vblank
= vblank
->count
;
1008 *vblanktime
= vblanktimestamp(dev
, pipe
, cur_vblank
);
1010 } while (cur_vblank
!= vblank
->count
&& --count
> 0);
1014 EXPORT_SYMBOL(drm_vblank_count_and_time
);
1017 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
1018 * and the system timestamp corresponding to that vblank counter value
1019 * @crtc: which counter to retrieve
1020 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
1022 * Fetches the "cooked" vblank count value that represents the number of
1023 * vblank events since the system was booted, including lost events due to
1024 * modesetting activity. Returns corresponding system timestamp of the time
1025 * of the vblank interval that corresponds to the current vblank counter value.
1027 * This is the native KMS version of drm_vblank_count_and_time().
1029 u32
drm_crtc_vblank_count_and_time(struct drm_crtc
*crtc
,
1030 struct timeval
*vblanktime
)
1032 return drm_vblank_count_and_time(crtc
->dev
, drm_crtc_index(crtc
),
1035 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time
);
1037 static void send_vblank_event(struct drm_device
*dev
,
1038 struct drm_pending_vblank_event
*e
,
1039 unsigned long seq
, struct timeval
*now
)
1041 e
->event
.sequence
= seq
;
1042 e
->event
.tv_sec
= now
->tv_sec
;
1043 e
->event
.tv_usec
= now
->tv_usec
;
1045 drm_send_event_locked(dev
, &e
->base
);
1047 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1052 * drm_arm_vblank_event - arm vblank event after pageflip
1055 * @e: the event to prepare to send
1057 * A lot of drivers need to generate vblank events for the very next vblank
1058 * interrupt. For example when the page flip interrupt happens when the page
1059 * flip gets armed, but not when it actually executes within the next vblank
1060 * period. This helper function implements exactly the required vblank arming
1063 * Caller must hold event lock. Caller must also hold a vblank reference for
1064 * the event @e, which will be dropped when the next vblank arrives.
1066 * This is the legacy version of drm_crtc_arm_vblank_event().
1068 void drm_arm_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1069 struct drm_pending_vblank_event
*e
)
1071 assert_spin_locked(&dev
->event_lock
);
1074 e
->event
.sequence
= drm_vblank_count(dev
, pipe
);
1075 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1077 EXPORT_SYMBOL(drm_arm_vblank_event
);
1080 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
1081 * @crtc: the source CRTC of the vblank event
1082 * @e: the event to send
1084 * A lot of drivers need to generate vblank events for the very next vblank
1085 * interrupt. For example when the page flip interrupt happens when the page
1086 * flip gets armed, but not when it actually executes within the next vblank
1087 * period. This helper function implements exactly the required vblank arming
1090 * Caller must hold event lock. Caller must also hold a vblank reference for
1091 * the event @e, which will be dropped when the next vblank arrives.
1093 * This is the native KMS version of drm_arm_vblank_event().
1095 void drm_crtc_arm_vblank_event(struct drm_crtc
*crtc
,
1096 struct drm_pending_vblank_event
*e
)
1098 drm_arm_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1100 EXPORT_SYMBOL(drm_crtc_arm_vblank_event
);
1103 * drm_send_vblank_event - helper to send vblank event after pageflip
1106 * @e: the event to send
1108 * Updates sequence # and timestamp on event, and sends it to userspace.
1109 * Caller must hold event lock.
1111 * This is the legacy version of drm_crtc_send_vblank_event().
1113 void drm_send_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1114 struct drm_pending_vblank_event
*e
)
1119 if (dev
->num_crtcs
> 0) {
1120 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1124 now
= get_drm_timestamp();
1127 send_vblank_event(dev
, e
, seq
, &now
);
1129 EXPORT_SYMBOL(drm_send_vblank_event
);
1132 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1133 * @crtc: the source CRTC of the vblank event
1134 * @e: the event to send
1136 * Updates sequence # and timestamp on event, and sends it to userspace.
1137 * Caller must hold event lock.
1139 * This is the native KMS version of drm_send_vblank_event().
1141 void drm_crtc_send_vblank_event(struct drm_crtc
*crtc
,
1142 struct drm_pending_vblank_event
*e
)
1144 drm_send_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1146 EXPORT_SYMBOL(drm_crtc_send_vblank_event
);
1149 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1154 * Zero on success or a negative error code on failure.
1156 static int drm_vblank_enable(struct drm_device
*dev
, unsigned int pipe
)
1158 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1161 assert_spin_locked(&dev
->vbl_lock
);
1163 spin_lock(&dev
->vblank_time_lock
);
1165 if (!vblank
->enabled
) {
1167 * Enable vblank irqs under vblank_time_lock protection.
1168 * All vblank count & timestamp updates are held off
1169 * until we are done reinitializing master counter and
1170 * timestamps. Filtercode in drm_handle_vblank() will
1171 * prevent double-accounting of same vblank interval.
1173 ret
= dev
->driver
->enable_vblank(dev
, pipe
);
1174 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe
, ret
);
1176 atomic_dec(&vblank
->refcount
);
1178 vblank
->enabled
= true;
1179 drm_update_vblank_count(dev
, pipe
, 0);
1183 spin_unlock(&dev
->vblank_time_lock
);
1189 * drm_vblank_get - get a reference count on vblank events
1191 * @pipe: index of CRTC to own
1193 * Acquire a reference count on vblank events to avoid having them disabled
1196 * This is the legacy version of drm_crtc_vblank_get().
1199 * Zero on success or a negative error code on failure.
1201 int drm_vblank_get(struct drm_device
*dev
, unsigned int pipe
)
1203 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1204 unsigned long irqflags
;
1207 if (!dev
->num_crtcs
)
1210 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1213 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1214 /* Going from 0->1 means we have to enable interrupts again */
1215 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
1216 ret
= drm_vblank_enable(dev
, pipe
);
1218 if (!vblank
->enabled
) {
1219 atomic_dec(&vblank
->refcount
);
1223 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1227 EXPORT_SYMBOL(drm_vblank_get
);
1230 * drm_crtc_vblank_get - get a reference count on vblank events
1231 * @crtc: which CRTC to own
1233 * Acquire a reference count on vblank events to avoid having them disabled
1236 * This is the native kms version of drm_vblank_get().
1239 * Zero on success or a negative error code on failure.
1241 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1243 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1245 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1248 * drm_vblank_put - release ownership of vblank events
1250 * @pipe: index of CRTC to release
1252 * Release ownership of a given vblank counter, turning off interrupts
1253 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1255 * This is the legacy version of drm_crtc_vblank_put().
1257 void drm_vblank_put(struct drm_device
*dev
, unsigned int pipe
)
1259 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1261 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1264 if (WARN_ON(atomic_read(&vblank
->refcount
) == 0))
1267 /* Last user schedules interrupt disable */
1268 if (atomic_dec_and_test(&vblank
->refcount
)) {
1269 if (drm_vblank_offdelay
== 0)
1271 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1272 vblank_disable_fn((unsigned long)vblank
);
1274 mod_timer(&vblank
->disable_timer
,
1275 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1278 EXPORT_SYMBOL(drm_vblank_put
);
1281 * drm_crtc_vblank_put - give up ownership of vblank events
1282 * @crtc: which counter to give up
1284 * Release ownership of a given vblank counter, turning off interrupts
1285 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1287 * This is the native kms version of drm_vblank_put().
1289 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1291 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1293 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1296 * drm_wait_one_vblank - wait for one vblank
1300 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1301 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1302 * due to lack of driver support or because the crtc is off.
1304 void drm_wait_one_vblank(struct drm_device
*dev
, unsigned int pipe
)
1306 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1310 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1313 ret
= drm_vblank_get(dev
, pipe
);
1314 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", pipe
, ret
))
1317 last
= drm_vblank_count(dev
, pipe
);
1319 ret
= wait_event_timeout(vblank
->queue
,
1320 last
!= drm_vblank_count(dev
, pipe
),
1321 msecs_to_jiffies(100));
1323 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", pipe
);
1325 drm_vblank_put(dev
, pipe
);
1327 EXPORT_SYMBOL(drm_wait_one_vblank
);
1330 * drm_crtc_wait_one_vblank - wait for one vblank
1333 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1334 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1335 * due to lack of driver support or because the crtc is off.
1337 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1339 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1341 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1344 * drm_vblank_off - disable vblank events on a CRTC
1348 * Drivers can use this function to shut down the vblank interrupt handling when
1349 * disabling a crtc. This function ensures that the latest vblank frame count is
1350 * stored so that drm_vblank_on() can restore it again.
1352 * Drivers must use this function when the hardware vblank counter can get
1353 * reset, e.g. when suspending.
1355 * This is the legacy version of drm_crtc_vblank_off().
1357 void drm_vblank_off(struct drm_device
*dev
, unsigned int pipe
)
1359 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1360 struct drm_pending_vblank_event
*e
, *t
;
1362 unsigned long irqflags
;
1365 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1368 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1370 spin_lock(&dev
->vbl_lock
);
1371 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1372 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1374 /* Avoid redundant vblank disables without previous drm_vblank_on(). */
1375 if (drm_core_check_feature(dev
, DRIVER_ATOMIC
) || !vblank
->inmodeset
)
1376 vblank_disable_and_save(dev
, pipe
);
1378 wake_up(&vblank
->queue
);
1381 * Prevent subsequent drm_vblank_get() from re-enabling
1382 * the vblank interrupt by bumping the refcount.
1384 if (!vblank
->inmodeset
) {
1385 atomic_inc(&vblank
->refcount
);
1386 vblank
->inmodeset
= 1;
1388 spin_unlock(&dev
->vbl_lock
);
1390 /* Send any queued vblank events, lest the natives grow disquiet */
1391 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1393 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1394 if (e
->pipe
!= pipe
)
1396 DRM_DEBUG("Sending premature vblank event on disable: "
1397 "wanted %d, current %d\n",
1398 e
->event
.sequence
, seq
);
1399 list_del(&e
->base
.link
);
1400 drm_vblank_put(dev
, pipe
);
1401 send_vblank_event(dev
, e
, seq
, &now
);
1403 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1405 EXPORT_SYMBOL(drm_vblank_off
);
1408 * drm_crtc_vblank_off - disable vblank events on a CRTC
1409 * @crtc: CRTC in question
1411 * Drivers can use this function to shut down the vblank interrupt handling when
1412 * disabling a crtc. This function ensures that the latest vblank frame count is
1413 * stored so that drm_vblank_on can restore it again.
1415 * Drivers must use this function when the hardware vblank counter can get
1416 * reset, e.g. when suspending.
1418 * This is the native kms version of drm_vblank_off().
1420 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1422 drm_vblank_off(crtc
->dev
, drm_crtc_index(crtc
));
1424 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1427 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1428 * @crtc: CRTC in question
1430 * Drivers can use this function to reset the vblank state to off at load time.
1431 * Drivers should use this together with the drm_crtc_vblank_off() and
1432 * drm_crtc_vblank_on() functions. The difference compared to
1433 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1434 * and hence doesn't need to call any driver hooks.
1436 void drm_crtc_vblank_reset(struct drm_crtc
*crtc
)
1438 struct drm_device
*dev
= crtc
->dev
;
1439 unsigned long irqflags
;
1440 unsigned int pipe
= drm_crtc_index(crtc
);
1441 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1443 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1445 * Prevent subsequent drm_vblank_get() from enabling the vblank
1446 * interrupt by bumping the refcount.
1448 if (!vblank
->inmodeset
) {
1449 atomic_inc(&vblank
->refcount
);
1450 vblank
->inmodeset
= 1;
1452 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1454 WARN_ON(!list_empty(&dev
->vblank_event_list
));
1456 EXPORT_SYMBOL(drm_crtc_vblank_reset
);
1459 * drm_vblank_on - enable vblank events on a CRTC
1463 * This functions restores the vblank interrupt state captured with
1464 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1465 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1466 * in driver load code to reflect the current hardware state of the crtc.
1468 * This is the legacy version of drm_crtc_vblank_on().
1470 void drm_vblank_on(struct drm_device
*dev
, unsigned int pipe
)
1472 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1473 unsigned long irqflags
;
1475 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1478 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1479 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1480 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1482 /* Drop our private "prevent drm_vblank_get" refcount */
1483 if (vblank
->inmodeset
) {
1484 atomic_dec(&vblank
->refcount
);
1485 vblank
->inmodeset
= 0;
1488 drm_reset_vblank_timestamp(dev
, pipe
);
1491 * re-enable interrupts if there are users left, or the
1492 * user wishes vblank interrupts to be enabled all the time.
1494 if (atomic_read(&vblank
->refcount
) != 0 || drm_vblank_offdelay
== 0)
1495 WARN_ON(drm_vblank_enable(dev
, pipe
));
1496 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1498 EXPORT_SYMBOL(drm_vblank_on
);
1501 * drm_crtc_vblank_on - enable vblank events on a CRTC
1502 * @crtc: CRTC in question
1504 * This functions restores the vblank interrupt state captured with
1505 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1506 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1507 * in driver load code to reflect the current hardware state of the crtc.
1509 * This is the native kms version of drm_vblank_on().
1511 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1513 drm_vblank_on(crtc
->dev
, drm_crtc_index(crtc
));
1515 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1518 * drm_vblank_pre_modeset - account for vblanks across mode sets
1522 * Account for vblank events across mode setting events, which will likely
1523 * reset the hardware frame counter.
1525 * This is done by grabbing a temporary vblank reference to ensure that the
1526 * vblank interrupt keeps running across the modeset sequence. With this the
1527 * software-side vblank frame counting will ensure that there are no jumps or
1530 * Unfortunately this approach is racy and also doesn't work when the vblank
1531 * interrupt stops running, e.g. across system suspend resume. It is therefore
1532 * highly recommended that drivers use the newer drm_vblank_off() and
1533 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1534 * using "cooked" software vblank frame counters and not relying on any hardware
1537 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1540 void drm_vblank_pre_modeset(struct drm_device
*dev
, unsigned int pipe
)
1542 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1544 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1545 if (!dev
->num_crtcs
)
1548 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1552 * To avoid all the problems that might happen if interrupts
1553 * were enabled/disabled around or between these calls, we just
1554 * have the kernel take a reference on the CRTC (just once though
1555 * to avoid corrupting the count if multiple, mismatch calls occur),
1556 * so that interrupts remain enabled in the interim.
1558 if (!vblank
->inmodeset
) {
1559 vblank
->inmodeset
= 0x1;
1560 if (drm_vblank_get(dev
, pipe
) == 0)
1561 vblank
->inmodeset
|= 0x2;
1564 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1567 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1571 * This function again drops the temporary vblank reference acquired in
1572 * drm_vblank_pre_modeset.
1574 void drm_vblank_post_modeset(struct drm_device
*dev
, unsigned int pipe
)
1576 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1577 unsigned long irqflags
;
1579 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1580 if (!dev
->num_crtcs
)
1583 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1586 if (vblank
->inmodeset
) {
1587 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1588 dev
->vblank_disable_allowed
= true;
1589 drm_reset_vblank_timestamp(dev
, pipe
);
1590 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1592 if (vblank
->inmodeset
& 0x2)
1593 drm_vblank_put(dev
, pipe
);
1595 vblank
->inmodeset
= 0;
1598 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1601 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1602 * @DRM_IOCTL_ARGS: standard ioctl arguments
1604 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1605 * ioctls around modesetting so that any lost vblank events are accounted for.
1607 * Generally the counter will reset across mode sets. If interrupts are
1608 * enabled around this call, we don't have to do anything since the counter
1609 * will have already been incremented.
1611 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1612 struct drm_file
*file_priv
)
1614 struct drm_modeset_ctl
*modeset
= data
;
1617 /* If drm_vblank_init() hasn't been called yet, just no-op */
1618 if (!dev
->num_crtcs
)
1621 /* KMS drivers handle this internally */
1622 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1625 pipe
= modeset
->crtc
;
1626 if (pipe
>= dev
->num_crtcs
)
1629 switch (modeset
->cmd
) {
1630 case _DRM_PRE_MODESET
:
1631 drm_vblank_pre_modeset(dev
, pipe
);
1633 case _DRM_POST_MODESET
:
1634 drm_vblank_post_modeset(dev
, pipe
);
1643 static int drm_queue_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1644 union drm_wait_vblank
*vblwait
,
1645 struct drm_file
*file_priv
)
1647 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1648 struct drm_pending_vblank_event
*e
;
1650 unsigned long flags
;
1654 e
= kzalloc(sizeof(*e
), GFP_KERNEL
);
1661 e
->base
.pid
= current
->pid
;
1662 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1663 e
->event
.base
.length
= sizeof(e
->event
);
1664 e
->event
.user_data
= vblwait
->request
.signal
;
1666 spin_lock_irqsave(&dev
->event_lock
, flags
);
1669 * drm_vblank_off() might have been called after we called
1670 * drm_vblank_get(). drm_vblank_off() holds event_lock
1671 * around the vblank disable, so no need for further locking.
1672 * The reference from drm_vblank_get() protects against
1673 * vblank disable from another source.
1675 if (!vblank
->enabled
) {
1680 ret
= drm_event_reserve_init_locked(dev
, file_priv
, &e
->base
,
1686 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1688 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1689 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1690 vblwait
->request
.sequence
= seq
+ 1;
1691 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1694 DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
1695 vblwait
->request
.sequence
, seq
, pipe
);
1697 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1698 vblwait
->request
.sequence
);
1700 e
->event
.sequence
= vblwait
->request
.sequence
;
1701 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1702 drm_vblank_put(dev
, pipe
);
1703 send_vblank_event(dev
, e
, seq
, &now
);
1704 vblwait
->reply
.sequence
= seq
;
1706 /* drm_handle_vblank_events will call drm_vblank_put */
1707 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1708 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1711 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1716 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1719 drm_vblank_put(dev
, pipe
);
1726 * \param inode device inode.
1727 * \param file_priv DRM file private.
1728 * \param cmd command.
1729 * \param data user argument, pointing to a drm_wait_vblank structure.
1730 * \return zero on success or a negative number on failure.
1732 * This function enables the vblank interrupt on the pipe requested, then
1733 * sleeps waiting for the requested sequence number to occur, and drops
1734 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1735 * after a timeout with no further vblank waits scheduled).
1737 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1738 struct drm_file
*file_priv
)
1740 struct drm_vblank_crtc
*vblank
;
1741 union drm_wait_vblank
*vblwait
= data
;
1743 unsigned int flags
, seq
, pipe
, high_pipe
;
1745 if (!dev
->irq_enabled
)
1748 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1751 if (vblwait
->request
.type
&
1752 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1753 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1754 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1755 vblwait
->request
.type
,
1756 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1757 _DRM_VBLANK_HIGH_CRTC_MASK
));
1761 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1762 high_pipe
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1764 pipe
= high_pipe
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1766 pipe
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1767 if (pipe
>= dev
->num_crtcs
)
1770 vblank
= &dev
->vblank
[pipe
];
1772 ret
= drm_vblank_get(dev
, pipe
);
1774 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1777 seq
= drm_vblank_count(dev
, pipe
);
1779 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1780 case _DRM_VBLANK_RELATIVE
:
1781 vblwait
->request
.sequence
+= seq
;
1782 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1783 case _DRM_VBLANK_ABSOLUTE
:
1790 if (flags
& _DRM_VBLANK_EVENT
) {
1791 /* must hold on to the vblank ref until the event fires
1792 * drm_vblank_put will be called asynchronously
1794 return drm_queue_vblank_event(dev
, pipe
, vblwait
, file_priv
);
1797 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1798 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1799 vblwait
->request
.sequence
= seq
+ 1;
1802 DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
1803 vblwait
->request
.sequence
, pipe
);
1804 vblank
->last_wait
= vblwait
->request
.sequence
;
1805 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1806 (((drm_vblank_count(dev
, pipe
) -
1807 vblwait
->request
.sequence
) <= (1 << 23)) ||
1809 !dev
->irq_enabled
));
1811 if (ret
!= -EINTR
) {
1814 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1815 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1816 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1818 DRM_DEBUG("returning %d to client\n",
1819 vblwait
->reply
.sequence
);
1821 DRM_DEBUG("vblank wait interrupted by signal\n");
1825 drm_vblank_put(dev
, pipe
);
1829 static void drm_handle_vblank_events(struct drm_device
*dev
, unsigned int pipe
)
1831 struct drm_pending_vblank_event
*e
, *t
;
1835 assert_spin_locked(&dev
->event_lock
);
1837 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1839 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1840 if (e
->pipe
!= pipe
)
1842 if ((seq
- e
->event
.sequence
) > (1<<23))
1845 DRM_DEBUG("vblank event on %d, current %d\n",
1846 e
->event
.sequence
, seq
);
1848 list_del(&e
->base
.link
);
1849 drm_vblank_put(dev
, pipe
);
1850 send_vblank_event(dev
, e
, seq
, &now
);
1853 trace_drm_vblank_event(pipe
, seq
);
1857 * drm_handle_vblank - handle a vblank event
1859 * @pipe: index of CRTC where this event occurred
1861 * Drivers should call this routine in their vblank interrupt handlers to
1862 * update the vblank counter and send any signals that may be pending.
1864 * This is the legacy version of drm_crtc_handle_vblank().
1866 bool drm_handle_vblank(struct drm_device
*dev
, unsigned int pipe
)
1868 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1869 unsigned long irqflags
;
1871 if (WARN_ON_ONCE(!dev
->num_crtcs
))
1874 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1877 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1879 /* Need timestamp lock to prevent concurrent execution with
1880 * vblank enable/disable, as this would cause inconsistent
1881 * or corrupted timestamps and vblank counts.
1883 spin_lock(&dev
->vblank_time_lock
);
1885 /* Vblank irq handling disabled. Nothing to do. */
1886 if (!vblank
->enabled
) {
1887 spin_unlock(&dev
->vblank_time_lock
);
1888 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1892 drm_update_vblank_count(dev
, pipe
, DRM_CALLED_FROM_VBLIRQ
);
1894 spin_unlock(&dev
->vblank_time_lock
);
1896 wake_up(&vblank
->queue
);
1897 drm_handle_vblank_events(dev
, pipe
);
1899 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1903 EXPORT_SYMBOL(drm_handle_vblank
);
1906 * drm_crtc_handle_vblank - handle a vblank event
1907 * @crtc: where this event occurred
1909 * Drivers should call this routine in their vblank interrupt handlers to
1910 * update the vblank counter and send any signals that may be pending.
1912 * This is the native KMS version of drm_handle_vblank().
1915 * True if the event was successfully handled, false on failure.
1917 bool drm_crtc_handle_vblank(struct drm_crtc
*crtc
)
1919 return drm_handle_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1921 EXPORT_SYMBOL(drm_crtc_handle_vblank
);
1924 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1926 * @pipe: CRTC for which to read the counter
1928 * Drivers can plug this into the .get_vblank_counter() function if
1929 * there is no useable hardware frame counter available.
1934 u32
drm_vblank_no_hw_counter(struct drm_device
*dev
, unsigned int pipe
)
1938 EXPORT_SYMBOL(drm_vblank_no_hw_counter
);