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Date:   Wed,  1 Nov 2023 01:28:45 +0000
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Message-ID: <20231101012845.2701348-1-badhri@google.com>
Subject: [PATCH v3] usb: typec: tcpm: Fix sink caps op current check
From:   Badhri Jagan Sridharan <badhri@google.com>
To:     gregkh@linuxfoundation.org, linux@roeck-us.net,
        heikki.krogerus@linux.intel.com
Cc:     kyletso@google.com, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Badhri Jagan Sridharan <badhri@google.com>
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TCPM checks for sink caps operational current even when PD is disabled.
This incorrectly sets tcpm_set_charge() when PD is disabled.
Check for sink caps only when PD is enabled.

[   97.572342] Start toggling
[   97.578949] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[   99.571648] CC1: 0 -> 0, CC2: 0 -> 4 [state TOGGLING, polarity 0, connected]
[   99.571658] state change TOGGLING -> SNK_ATTACH_WAIT [rev3 NONE_AMS]
[   99.571673] pending state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED @ 170 ms [rev3 NONE_AMS]
[   99.741778] state change SNK_ATTACH_WAIT -> SNK_DEBOUNCED [delayed 170 ms]
[   99.789283] CC1: 0 -> 0, CC2: 4 -> 5 [state SNK_DEBOUNCED, polarity 0, connected]
[   99.789306] state change SNK_DEBOUNCED -> SNK_DEBOUNCED [rev3 NONE_AMS]
[   99.903584] VBUS on
[   99.903591] state change SNK_DEBOUNCED -> SNK_ATTACHED [rev3 NONE_AMS]
[   99.903600] polarity 1
[   99.910155] enable vbus discharge ret:0
[   99.910160] Requesting mux state 1, usb-role 2, orientation 2
[   99.946791] state change SNK_ATTACHED -> SNK_STARTUP [rev3 NONE_AMS]
[   99.946798] state change SNK_STARTUP -> SNK_DISCOVERY [rev3 NONE_AMS]
[   99.946800] Setting voltage/current limit 5000 mV 500 mA
[   99.946803] vbus=0 charge:=1
[  100.027139] state change SNK_DISCOVERY -> SNK_READY [rev3 NONE_AMS]
[  100.027145] Setting voltage/current limit 5000 mV 3000 mA
[  100.466830] VBUS on

Cc: stable@vger.kernel.org
Fixes: 803b1c8a0cea ("usb: typec: tcpm: not sink vbus if operational current is 0mA")
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
Changes since v2:
* Fix the "Fixes" tag
* Refactor code based on Guenter Roeck's suggestion.

Changes since v1:
* Fix commit title and description to address comments from Guenter Roeck
---
 drivers/usb/typec/tcpm/tcpm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 058d5b853b57..afc791ab6d4f 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4273,7 +4273,8 @@ static void run_state_machine(struct tcpm_port *port)
 				current_lim = PD_P_SNK_STDBY_MW / 5;
 			tcpm_set_current_limit(port, current_lim, 5000);
 			/* Not sink vbus if operational current is 0mA */
-			tcpm_set_charge(port, !!pdo_max_current(port->snk_pdo[0]));
+			tcpm_set_charge(port, !port->pd_supported ||
+					pdo_max_current(port->snk_pdo[0]));
 
 			if (!port->pd_supported)
 				tcpm_set_state(port, SNK_READY, 0);

base-commit: c70793fb7632a153862ee9060e6d48131469a29c
-- 
2.42.0.820.g83a721a137-goog