[PATCH 1/2] usb: typec: ucsi: Check if power role change actually happened before handling

[Myrrh Periwinkle]

The CrOS EC may send a connector status change event with the power
direction changed flag set even if the power direction hasn't actually
changed after initiating a SET_PDR command internally [1]. In practice
this happens on every system suspend due to other changes performed by
the EC [2][3][4], causing suspend to fail.

Fix this by checking if the power role change actually happened before
handling it.

[1]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/subsys/pd_controller/pdc_power_mgmt.c;l=1689;drc=2d5a1cffce4e5ac8a39442cb3b764d2d5e1cf794
[2]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/subsys/pd_controller/pdc_power_mgmt.c;l=3923;drc=2d5a1cffce4e5ac8a39442cb3b764d2d5e1cf794
[3]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/subsys/pd_controller/pdc_power_mgmt.c;l=5094;drc=2d5a1cffce4e5ac8a39442cb3b764d2d5e1cf794
[4]: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/zephyr/subsys/pd_controller/pdc_power_mgmt.c;l=2229;drc=2d5a1cffce4e5ac8a39442cb3b764d2d5e1cf794

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 7616f006db07 ("usb: typec: ucsi: Update power_supply on power role change")
Signed-off-by: Myrrh Periwinkle <myrrhperiwinkle@xxxxxxxxxxx>
---
 drivers/usb/typec/ucsi/ucsi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index 5b7ad9e99cb9..e19b656609e4 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1277,7 +1277,7 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 						  work);
 	struct ucsi *ucsi = con->ucsi;
 	u8 curr_scale, volt_scale;
-	enum typec_role role;
+	enum typec_role role, prev_role;
 	u16 change;
 	int ret;
 	u32 val;
@@ -1288,6 +1288,8 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 		dev_err_once(ucsi->dev, "%s entered without EVENT_PENDING\n",
 			     __func__);
 
+	prev_role = UCSI_CONSTAT(con, PWR_DIR);
+
 	ret = ucsi_get_connector_status(con, true);
 	if (ret) {
 		dev_err(ucsi->dev, "%s: GET_CONNECTOR_STATUS failed (%d)\n",
@@ -1304,7 +1306,7 @@ static void ucsi_handle_connector_change(struct work_struct *work)
 	change = UCSI_CONSTAT(con, CHANGE);
 	role = UCSI_CONSTAT(con, PWR_DIR);
 
-	if (change & UCSI_CONSTAT_POWER_DIR_CHANGE) {
+	if ((change & UCSI_CONSTAT_POWER_DIR_CHANGE) && role != prev_role) {
 		typec_set_pwr_role(con->port, role);
 		ucsi_port_psy_changed(con);
 

-- 
2.54.0