diff mbox series

[1/5] usb: typec: ucsi: Clear EVENT_PENDING under PPM lock

Message ID 20240320073927.1641788-2-lk@c--e.de (mailing list archive)
State Accepted
Commit 15b2e71b4653b3e13df34695a29ebeee237c5af2
Headers show
Series Fix various races in UCSI | expand

Commit Message

Christian A. Ehrhardt March 20, 2024, 7:39 a.m. UTC 
Suppose we sleep on the PPM lock after clearing the EVENT_PENDING
bit because the thread for another connector is executing a command.
In this case the command completion of the other command will still
report the connector change for our connector.

Clear the EVENT_PENDING bit under the PPM lock to avoid another
useless call to ucsi_handle_connector_change() in this case.

Fixes: c9aed03a0a68 ("usb: ucsi: Add missing ppm_lock")
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
---
 drivers/usb/typec/ucsi/ucsi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Heikki Krogerus March 22, 2024, 9:53 a.m. UTC | #1 
On Wed, Mar 20, 2024 at 08:39:22AM +0100, Christian A. Ehrhardt wrote:
> Suppose we sleep on the PPM lock after clearing the EVENT_PENDING
> bit because the thread for another connector is executing a command.
> In this case the command completion of the other command will still
> report the connector change for our connector.
> 
> Clear the EVENT_PENDING bit under the PPM lock to avoid another
> useless call to ucsi_handle_connector_change() in this case.
> 
> Fixes: c9aed03a0a68 ("usb: ucsi: Add missing ppm_lock")
> Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/usb/typec/ucsi/ucsi.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
> index cf52cb34d285..8a6645ffd938 100644
> --- a/drivers/usb/typec/ucsi/ucsi.c
> +++ b/drivers/usb/typec/ucsi/ucsi.c
> @@ -1215,11 +1215,11 @@ static void ucsi_handle_connector_change(struct work_struct *work)
>  	if (con->status.change & UCSI_CONSTAT_CAM_CHANGE)
>  		ucsi_partner_task(con, ucsi_check_altmodes, 1, 0);
>  
> -	clear_bit(EVENT_PENDING, &con->ucsi->flags);
> -
>  	mutex_lock(&ucsi->ppm_lock);
> +	clear_bit(EVENT_PENDING, &con->ucsi->flags);
>  	ret = ucsi_acknowledge_connector_change(ucsi);
>  	mutex_unlock(&ucsi->ppm_lock);
> +
>  	if (ret)
>  		dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret);
>  
> -- 
> 2.40.1
diff mbox series

Patch

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c
index cf52cb34d285..8a6645ffd938 100644
--- a/drivers/usb/typec/ucsi/ucsi.c
+++ b/drivers/usb/typec/ucsi/ucsi.c
@@ -1215,11 +1215,11 @@  static void ucsi_handle_connector_change(struct work_struct *work)
 	if (con->status.change & UCSI_CONSTAT_CAM_CHANGE)
 		ucsi_partner_task(con, ucsi_check_altmodes, 1, 0);
 
-	clear_bit(EVENT_PENDING, &con->ucsi->flags);
-
 	mutex_lock(&ucsi->ppm_lock);
+	clear_bit(EVENT_PENDING, &con->ucsi->flags);
 	ret = ucsi_acknowledge_connector_change(ucsi);
 	mutex_unlock(&ucsi->ppm_lock);
+
 	if (ret)
 		dev_err(ucsi->dev, "%s: ACK failed (%d)", __func__, ret);