V4L/DVB (10650): uvcvideo: Initialize streaming parameters with the probe control value
The UVC specification requires SET_CUR requests on the streaming commit control
to use values retrieved from a successful GET_CUR request on the probe control.
Initialize streaming parameters with the probe control current value to make
sure the driver always complies.
Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index 7ebb895..9139086 100644
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -1026,11 +1026,20 @@
*/
usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
- /* Some webcams don't suport GET_DEF requests on the probe control. We
- * fall back to GET_CUR if GET_DEF fails.
+ /* Set the streaming probe control with default streaming parameters
+ * retrieved from the device. Webcams that don't suport GET_DEF
+ * requests on the probe control will just keep their current streaming
+ * parameters.
*/
- if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 &&
- (ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0)
+ if (uvc_get_video_ctrl(video, probe, 1, GET_DEF) == 0)
+ uvc_set_video_ctrl(video, probe, 1);
+
+ /* Initialize the streaming parameters with the probe control current
+ * value. This makes sure SET_CUR requests on the streaming commit
+ * control will always use values retrieved from a successful GET_CUR
+ * request on the probe control, as required by the UVC specification.
+ */
+ if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0)
return ret;
/* Check if the default format descriptor exists. Use the first