| Message ID | 20241203-uvc-fix-async-v6-5-26c867231118@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | media: uvcvideo: Two +1 fixes for async controls | expand |
Hi Ricardo, Thank you for the patch. On Tue, Dec 03, 2024 at 09:20:12PM +0000, Ricardo Ribalda wrote: > Asynchronous controls trigger an event when they have completed their > operation. > > This can make that the control cached value does not match the value in > the device. > > Let's flush the cache to be on the safe side. > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > --- > drivers/media/usb/uvc/uvc_ctrl.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index 3dc9b7a49f64..db29e0e8bfd4 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1622,6 +1622,9 @@ void uvc_ctrl_status_event(struct uvc_video_chain *chain, > > mutex_lock(&chain->ctrl_mutex); > > + /* Flush the control cache, the data might have changed. */ > + ctrl->loaded = 0; > + That's better, covered by ctrl_mutex. There are however quite a few code paths through which ctrl->loaded is accessed without holding the mutex :-( Not a candidate for this series, but this should eventually be fixed. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > handle = ctrl->handle; > if (handle) > uvc_ctrl_set_handle(handle, ctrl, NULL); >
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index 3dc9b7a49f64..db29e0e8bfd4 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1622,6 +1622,9 @@ void uvc_ctrl_status_event(struct uvc_video_chain *chain, mutex_lock(&chain->ctrl_mutex); + /* Flush the control cache, the data might have changed. */ + ctrl->loaded = 0; + handle = ctrl->handle; if (handle) uvc_ctrl_set_handle(handle, ctrl, NULL);
Asynchronous controls trigger an event when they have completed their operation. This can make that the control cached value does not match the value in the device. Let's flush the cache to be on the safe side. Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> --- drivers/media/usb/uvc/uvc_ctrl.c | 3 +++ 1 file changed, 3 insertions(+)