media: uvcvideo: Flush the control cache when we get an event

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 <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Laurent Pinchart <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

Author: ribalda

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);