Re: [PATCH v2] usb: typec: tcpm: Add additional checks for contaminant

On Sun, Oct 15, 2023 at 05:31:08AM +0000, Badhri Jagan Sridharan wrote:

When transitioning from SNK_DEBOUNCED to unattached, its worthwhile to check for contaminant to mitigate wakeups.

[81334.219571] Start toggling
[81334.228220] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[81334.305147] CC1: 0 -> 0, CC2: 0 -> 3 [state TOGGLING, polarity 0, connected]
[81334.305162] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
[81334.305187] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
[81334.475515] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms]
[81334.486480] CC1: 0 -> 0, CC2: 3 -> 0 [state SNK_DEBOUNCED, polarity 0, disconnected]
[81334.486495] state change SNK_DEBOUNCED -> SNK_DEBOUNCED [rev3 NONE_AMS]
[81334.486515] pending state change SNK_DEBOUNCED -> SNK_UNATTACHED @ 20 ms [rev3 NONE_AMS]
[81334.506621] state change SNK_DEBOUNCED -> SNK_UNATTACHED [delayed 20 ms]
[81334.506640] Start toggling
[81334.516972] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[81334.592759] CC1: 0 -> 0, CC2: 0 -> 3 [state TOGGLING, polarity 0, connected]
[81334.592773] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
[81334.592792] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
[81334.762940] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms]
[81334.773557] CC1: 0 -> 0, CC2: 3 -> 0 [state SNK_DEBOUNCED, polarity 0, disconnected]
[81334.773570] state change SNK_DEBOUNCED -> SNK_DEBOUNCED [rev3 NONE_AMS]
[81334.773588] pending state change SNK_DEBOUNCED -> SNK_UNATTACHED @ 20 ms [rev3 NONE_AMS]
[81334.793672] state change SNK_DEBOUNCED -> SNK_UNATTACHED [delayed 20 ms]
[81334.793681] Start toggling
[81334.801840] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[81334.878655] CC1: 0 -> 0, CC2: 0 -> 3 [state TOGGLING, polarity 0, connected]
[81334.878672] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
[81334.878696] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
[81335.048968] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms]
[81335.060684] CC1: 0 -> 0, CC2: 3 -> 0 [state SNK_DEBOUNCED, polarity 0, disconnected]
[81335.060754] state change SNK_DEBOUNCED -> SNK_DEBOUNCED [rev3 NONE_AMS]
[81335.060775] pending state change SNK_DEBOUNCED -> SNK_UNATTACHED @ 20 ms [rev3 NONE_AMS]
[81335.080884] state change SNK_DEBOUNCED -> SNK_UNATTACHED [delayed 20 ms]
[81335.080900] Start toggling

Cc: stable@vger.kernel.org Fixes: 599f008c257d ("usb: typec: tcpm: Add callbacks to mitigate wakeups due to contaminant") Signed-off-by: Badhri Jagan Sridharan badhri@google.com

Acked-by: Heikki Krogerus heikki.krogerus@linux.intel.com

---

drivers/usb/typec/tcpm/tcpm.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 6e843c511b85..1c7e8dc5282d 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -3903,6 +3903,8 @@ static void run_state_machine(struct tcpm_port *port) port->potential_contaminant = ((port->enter_state == SRC_ATTACH_WAIT && port->state == SRC_UNATTACHED) || (port->enter_state == SNK_ATTACH_WAIT &&

• 				port->state == SNK_UNATTACHED) ||
  

• 			       (port->enter_state == SNK_DEBOUNCED &&
  			port->state == SNK_UNATTACHED));
  

port->enter_state = port->state;

base-commit: 1034cc423f1b4a7a9a56d310ca980fcd2753e11d

2.42.0.655.g421f12c284-goog