On Fri, 7 Oct 2022 at 15:20, <quic_mmitkov@xxxxxxxxxxx> wrote:
>
> From: Milen Mitkov <quic_mmitkov@xxxxxxxxxxx>
>
> Use the multistream series function video_device_pipeline_alloc_start
> to allows multiple clients of the same pipeline.
>
> If any of the entities in the pipeline doesn't return success at stop
> (e.g. if a VFE line remains running), the full pipeline won't be stopped.
> This allows for stopping and starting streams at any point without
> disrupting the other running streams.
>
> Signed-off-by: Milen Mitkov <quic_mmitkov@xxxxxxxxxxx>
> ---
> .../media/platform/qcom/camss/camss-video.c | 21 ++++++++++++++++---
> 1 file changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/platform/qcom/camss/camss-video.c b/drivers/media/platform/qcom/camss/camss-video.c
> index 81fb3a5bc1d5..b042faf3dcda 100644
> --- a/drivers/media/platform/qcom/camss/camss-video.c
> +++ b/drivers/media/platform/qcom/camss/camss-video.c
> @@ -353,6 +353,7 @@ static int video_get_subdev_format(struct camss_video *video,
>
> fmt.pad = pad;
> fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> + fmt.stream = 0;
>
> ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
> if (ret)
> @@ -493,9 +494,11 @@ static int video_start_streaming(struct vb2_queue *q, unsigned int count)
> struct v4l2_subdev *subdev;
> int ret;
>
> - ret = video_device_pipeline_start(vdev, &video->pipe);
> - if (ret < 0)
> + ret = video_device_pipeline_alloc_start(vdev);
> + if (ret < 0) {
> + dev_err(video->camss->dev, "Failed to start media pipeline: %d\n", ret);
> return ret;
> + }
>
> ret = video_check_format(video);
> if (ret < 0)
> @@ -536,6 +539,7 @@ static void video_stop_streaming(struct vb2_queue *q)
> struct media_entity *entity;
> struct media_pad *pad;
> struct v4l2_subdev *subdev;
> + int ret;
>
> entity = &vdev->entity;
> while (1) {
> @@ -550,7 +554,18 @@ static void video_stop_streaming(struct vb2_queue *q)
> entity = pad->entity;
> subdev = media_entity_to_v4l2_subdev(entity);
>
> - v4l2_subdev_call(subdev, video, s_stream, 0);
> + ret = v4l2_subdev_call(subdev, video, s_stream, 0);
> +
> + if (ret == -EBUSY) {
> + /* Don't stop if other instances of the pipeline are still running */
> + dev_dbg(video->camss->dev, "Video pipeline still used, don't stop streaming.\n");
> + return;
> + }
> +
> + if (ret) {
> + dev_err(video->camss->dev, "Video pipeline stop failed: %d\n", ret);
> + return;
> + }
> }
>
> video_device_pipeline_stop(vdev);
> --
> 2.37.3
>
Reviewed-by: Robert Foss <robert.foss@xxxxxxxxxx>
