From de5ac4d46304b385df999715f2ea36d84a1914f5 Mon Sep 17 00:00:00 2001
From: Badhri Jagan Sridharan <badhri@google.com>
Date: Sun, 15 Oct 2023 05:31:08 +0000
Subject: [PATCH] usb: typec: tcpm: Add additional checks for contaminant
commit 1a4a2df07c1f087704c24282cebe882268e38146 upstream.
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>
Link: https://lore.kernel.org/r/20231015053108.2349570-1-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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 1596afee6c86..be1bd83a506a 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -3970,6 +3970,8 @@ 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;
--
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