Commit f6ec9bb4 authored by Xu Yang's avatar Xu Yang Committed by Greg Kroah-Hartman
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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 8db73e6a ("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: 8db73e6a ("usb: typec: tcpm: allow sink (ufp) to toggle into accessory mode debug")
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarXu Yang <xu.yang_2@nxp.com>
Acked-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: default avatarAmit Sunil Dhamne <amitsd@google.com>
Link: https://patch.msgid.link/20260424074009.2979266-1-xu.yang_2@nxp.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2909f0d4

drivers/usb/typec/tcpm/tcpm.c

+16 −9
Original line number Diff line number Diff line
@@ -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;