[PATCH v1] usb: typec: tcpm: Return ENOTSUPP for power supply prop writes

From: Badhri Jagan Sridharan
Date: Tue Aug 16 2022 - 03:09:20 EST


When the port does not support USB PD, prevent transition to PD
only states when power supply property is written. In this case,
TCPM transitions to SNK_NEGOTIATE_CAPABILITIES
which should not be the case given that the port is not pd_capable.

[ 84.308251] state change SNK_READY -> SNK_NEGOTIATE_CAPABILITIES [rev3 NONE_AMS]
[ 84.308335] Setting usb_comm capable false
[ 84.323367] set_auto_vbus_discharge_threshold mode:3 pps_active:n vbus:5000 ret:0
[ 84.323376] state change SNK_NEGOTIATE_CAPABILITIES -> SNK_WAIT_CAPABILITIES [rev3 NONE_AMS]

Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
---
drivers/usb/typec/tcpm/tcpm.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index ea5a917c51b1..904c7b4ce2f0 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -6320,6 +6320,13 @@ static int tcpm_psy_set_prop(struct power_supply *psy,
struct tcpm_port *port = power_supply_get_drvdata(psy);
int ret;

+ /*
+ * All the properties below are related to USB PD. The check needs to be
+ * property specific when a non-pd related property is added.
+ */
+ if (!port->pd_supported)
+ return -EOPNOTSUPP;
+
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
ret = tcpm_psy_set_online(port, val);
--
2.37.1.595.g718a3a8f04-goog