usb: typec: tcpm: fix debug accessory mode detection for sink ports

The port in debug accessory mode can be either a source or sink. The
previous tcpm_port_is_debug() function only checked for source port.

Commit 8db73e6a42b6 ("usb: typec: tcpm: allow sink (ufp) to toggle into
accessory mode debug") changed the detection logic to support both roles,
but left some logic in _tcpm_cc_change() unchanged, This causes the state
machine to transition to an incorrect state when operating as a sink in
debug accessory mode. Log as below:

[  978.637541] CC1: 0 -> 5, CC2: 0 -> 5 [state TOGGLING, polarity 0, connected]
[  978.637567] state change TOGGLING -> SRC_ATTACH_WAIT [rev1 NONE_AMS]
[  978.637596] pending state change SRC_ATTACH_WAIT -> DEBUG_ACC_ATTACHED @ 180 ms [rev1 NONE_AMS]
[  978.647098] CC1: 5 -> 0, CC2: 5 -> 5 [state SRC_ATTACH_WAIT, polarity 0, connected]
[  978.647115] state change SRC_ATTACH_WAIT -> SRC_ATTACH_WAIT [rev1 NONE_AMS]

It should go to SNK_ATTACH_WAIT instead of SRC_ATTACH_WAIT state.

To fix this, add tcpm_port_is_debug_source() and tcpm_port_is_debug_sink()
helper to explicitly identify the power mode in debug accessory mode.
Update the state transition logic in _tcpm_cc_change() to ensure the state
machine transitions comply with Type-C specification. Also update the logic
in run_state_machine() to keep consistency.

Fixes: 8db73e6a42b6 ("usb: typec: tcpm: allow sink (ufp) to toggle into accessory mode debug")
Cc: stable <stable@kernel.org>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Amit Sunil Dhamne <amitsd@google.com>
Link: https://patch.msgid.link/20260424074009.2979266-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index cd5560d6f19e1968b2eef2570ee415a21fe3fcb8..55fee96d3342add8db4641e1cd4331a73579bb7a 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -732,9 +732,14 @@ static const char * const pd_rev[] = {
         (tcpm_cc_is_source((port)->cc2) && \
          !tcpm_cc_is_source((port)->cc1)))
 
+#define tcpm_port_is_debug_source(port) \
+       (tcpm_cc_is_source((port)->cc1) && tcpm_cc_is_source((port)->cc2))
+
+#define tcpm_port_is_debug_sink(port) \
+       (tcpm_cc_is_sink((port)->cc1) && tcpm_cc_is_sink((port)->cc2))
+
 #define tcpm_port_is_debug(port) \
-       ((tcpm_cc_is_source((port)->cc1) && tcpm_cc_is_source((port)->cc2)) || \
-        (tcpm_cc_is_sink((port)->cc1) && tcpm_cc_is_sink((port)->cc2)))
+       (tcpm_port_is_debug_source(port) || tcpm_port_is_debug_sink(port))
 
 #define tcpm_port_is_audio(port) \
        (tcpm_cc_is_audio((port)->cc1) && tcpm_cc_is_audio((port)->cc2))
@@ -5176,7 +5181,7 @@ static void run_state_machine(struct tcpm_port *port)
                        tcpm_set_state(port, SNK_UNATTACHED, PD_T_DRP_SNK);
                break;
        case SRC_ATTACH_WAIT:
-               if (tcpm_port_is_debug(port))
+               if (tcpm_port_is_debug_source(port))
                        tcpm_set_state(port, DEBUG_ACC_ATTACHED,
                                       port->timings.cc_debounce_time);
                else if (tcpm_port_is_audio(port))
@@ -5434,7 +5439,7 @@ static void run_state_machine(struct tcpm_port *port)
                        tcpm_set_state(port, SRC_UNATTACHED, PD_T_DRP_SRC);
                break;
        case SNK_ATTACH_WAIT:
-               if (tcpm_port_is_debug(port))
+               if (tcpm_port_is_debug_sink(port))
                        tcpm_set_state(port, DEBUG_ACC_ATTACHED,
                                       PD_T_CC_DEBOUNCE);
                else if (tcpm_port_is_audio(port))
@@ -5454,7 +5459,7 @@ static void run_state_machine(struct tcpm_port *port)
                if (tcpm_port_is_disconnected(port))
                        tcpm_set_state(port, SNK_UNATTACHED,
                                       PD_T_PD_DEBOUNCE);
-               else if (tcpm_port_is_debug(port))
+               else if (tcpm_port_is_debug_sink(port))
                        tcpm_set_state(port, DEBUG_ACC_ATTACHED,
                                       PD_T_CC_DEBOUNCE);
                else if (tcpm_port_is_audio(port))
@@ -6362,10 +6367,10 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
 
        switch (port->state) {
        case TOGGLING:
-               if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
+               if (tcpm_port_is_debug_source(port) || tcpm_port_is_audio(port) ||
                    tcpm_port_is_source(port))
                        tcpm_set_state(port, SRC_ATTACH_WAIT, 0);
-               else if (tcpm_port_is_sink(port))
+               else if (tcpm_port_is_debug_sink(port) || tcpm_port_is_sink(port))
                        tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
                break;
        case CHECK_CONTAMINANT:
@@ -6373,9 +6378,11 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
                break;
        case SRC_UNATTACHED:
        case ACC_UNATTACHED:
-               if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
+               if (tcpm_port_is_debug_source(port) || tcpm_port_is_audio(port) ||
                    tcpm_port_is_source(port))
                        tcpm_set_state(port, SRC_ATTACH_WAIT, 0);
+               else if (tcpm_port_is_debug_sink(port))
+                       tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
                break;
        case SRC_ATTACH_WAIT:
                if (tcpm_port_is_disconnected(port) ||
@@ -6397,7 +6404,7 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
                }
                break;
        case SNK_UNATTACHED:
-               if (tcpm_port_is_debug(port) || tcpm_port_is_audio(port) ||
+               if (tcpm_port_is_debug_sink(port) || tcpm_port_is_audio(port) ||
                    tcpm_port_is_sink(port))
                        tcpm_set_state(port, SNK_ATTACH_WAIT, 0);
                break;