From: Xu Yang <xu.yang_2@nxp.com>
To: badhri@google.com, heikki.krogerus@linux.intel.com,
gregkh@linuxfoundation.org, m.grzeschik@pengutronix.de
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
imx@lists.linux.dev, jun.li@nxp.com
Subject: [PATCH] usb: typec: tcpm: fix debug accessory mode detection for sink ports
Date: Mon, 20 Apr 2026 11:03:17 +0800 [thread overview]
Message-ID: <20260420030317.425022-1-xu.yang_2@nxp.com> (raw)
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.
Fixes: 8db73e6a42b6 ("usb: typec: tcpm: allow sink (ufp) to toggle into accessory mode debug")
Cc: stable@vger.kernel.org
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
---
drivers/usb/typec/tcpm/tcpm.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index dfbb94ddc98a..1ee00025de56 100644
--- 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))
@@ -6360,10 +6365,10 @@ 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:
@@ -6371,9 +6376,11 @@ 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) ||
@@ -6395,7 +6402,7 @@ 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;
--
2.34.1
reply other threads:[~2026-04-20 3:01 UTC|newest]
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