Re: [PATCH v4 3/5] media: uvcvideo: Split uvc_stop_streaming()

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Mon, Jun 30, 2025 at 02:59:05PM +0200, Hans de Goede wrote:
> On 17-Jun-25 11:27 AM, Hans Verkuil wrote:
> > On 16/06/2025 17:24, Ricardo Ribalda wrote:
> >> uvc_stop_streaming() is used for meta and video nodes. Split the function
> >> in two to avoid confusion.
> >>
> >> Use this opportunity to rename uvc_start_streaming() to
> >> uvc_start_streaming_video(), as it is only called by the video nodes.
> >>
> >> Reviewed-by: Hans de Goede <hansg@kernel.org>
> >> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> >> ---
> >>  drivers/media/usb/uvc/uvc_queue.c | 22 +++++++++++++++-------
> >>  1 file changed, 15 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> >> index 8f9737ac729546683ca48f5e71ce3dfacbae2926..3f357c2d48cfd258c26f0342007d1d12f1e01007 100644
> >> --- a/drivers/media/usb/uvc/uvc_queue.c
> >> +++ b/drivers/media/usb/uvc/uvc_queue.c
> >> @@ -167,7 +167,7 @@ static void uvc_buffer_finish(struct vb2_buffer *vb)
> >>  		uvc_video_clock_update(stream, vbuf, buf);
> >>  }
> >>  
> >> -static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
> >> +static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
> >>  {
> >>  	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
> >>  	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
> >> @@ -186,14 +186,22 @@ static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
> >>  	return ret;
> >>  }
> >>  
> >> -static void uvc_stop_streaming(struct vb2_queue *vq)
> >> +static void uvc_stop_streaming_video(struct vb2_queue *vq)
> >>  {
> >>  	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
> >>  
> >>  	lockdep_assert_irqs_enabled();
> >>  
> >> -	if (vq->type != V4L2_BUF_TYPE_META_CAPTURE)
> >> -		uvc_video_stop_streaming(uvc_queue_to_stream(queue));
> >> +	uvc_video_stop_streaming(uvc_queue_to_stream(queue));
> >> +
> >> +	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
> >> +}
> >> +
> >> +static void uvc_stop_streaming_meta(struct vb2_queue *vq)
> >> +{
> >> +	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
> >> +
> >> +	lockdep_assert_irqs_enabled();
> >>  
> >>  	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
> >>  }
> >> @@ -203,15 +211,15 @@ static const struct vb2_ops uvc_queue_qops = {
> >>  	.buf_prepare = uvc_buffer_prepare,
> >>  	.buf_queue = uvc_buffer_queue,
> >>  	.buf_finish = uvc_buffer_finish,
> >> -	.start_streaming = uvc_start_streaming,
> >> -	.stop_streaming = uvc_stop_streaming,
> >> +	.start_streaming = uvc_start_streaming_video,
> >> +	.stop_streaming = uvc_stop_streaming_video,
> >>  };
> >>  
> >>  static const struct vb2_ops uvc_meta_queue_qops = {
> >>  	.queue_setup = uvc_queue_setup,
> >>  	.buf_prepare = uvc_buffer_prepare,
> >>  	.buf_queue = uvc_buffer_queue,
> >> -	.stop_streaming = uvc_stop_streaming,
> >> +	.stop_streaming = uvc_stop_streaming_meta,
> >>  };
> > 
> > I think there should be a comment stating that the metadata stream
> > expects that video is streaming, it does not start streaming by itself.
> > 
> > Something like:
> > 
> > 	/*
> > 	 * .start_streaming is not provided here. Metadata relies on
> > 	 * video streaming being active. If video isn't streaming, then
> > 	 * no metadata will arrive either.
> > 	 */
> > 
> > It's unexpected that there is no start_streaming for metadata, so a
> > comment wouldn't hurt.
> 
> I've added this comment while merging this series and I've now pushed
> the entire series to uvc.git/for-next .
> 
> BTW it seems that both uvc.git/next and uvc.git/for-next are in
> use now?  With uvc.git/next seemingly following media-commiters/next ?

As far as I understand, some jobs in the media CI use the next branch,
for instance the bisect job that tries to compile every commit uses the
next branch as a base. We therefore need to keep the next branch
up-to-date, mirroring upstream.

> I thought we had agreed to only use uvc.git/for-next ?

-- 
Regards,

Laurent Pinchart