Re: [RFCv4 PATCH 7/8] vb2: return ENODATA in start_streaming in case of too few buffers.

[Hans Verkuil <hverkuil@xs4all.nl>]

As Guennadi mentioned in his review, ENODATA will be replaced by ENOBUFS, which is
more appropriate.

Prabhakar, Kamil, Tomasz, are you OK with this patch provided s/ENODATA/ENOBUFS/ ?

Regards,

	Hans

On 12/09/2013 02:43 PM, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> This works together with the retry_start_streaming mechanism to allow userspace
> to start streaming even if not all required buffers have been queued.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> Cc: Lad, Prabhakar <prabhakar.csengg@gmail.com>
> Cc: Tomasz Stanislawski <t.stanislaws@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Kamil Debski <k.debski@samsung.com>
> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
>  drivers/media/platform/davinci/vpbe_display.c   | 2 +-
>  drivers/media/platform/davinci/vpif_capture.c   | 2 +-
>  drivers/media/platform/davinci/vpif_display.c   | 2 +-
>  drivers/media/platform/s5p-mfc/s5p_mfc_enc.c    | 2 +-
>  drivers/media/platform/s5p-tv/mixer_video.c     | 2 +-
>  drivers/media/platform/soc_camera/mx2_camera.c  | 2 +-
>  drivers/staging/media/davinci_vpfe/vpfe_video.c | 2 ++
>  7 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/media/platform/davinci/vpbe_display.c b/drivers/media/platform/davinci/vpbe_display.c
> index eac472b..53be7fc 100644
> --- a/drivers/media/platform/davinci/vpbe_display.c
> +++ b/drivers/media/platform/davinci/vpbe_display.c
> @@ -347,7 +347,7 @@ static int vpbe_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	/* If buffer queue is empty, return error */
>  	if (list_empty(&layer->dma_queue)) {
>  		v4l2_err(&vpbe_dev->v4l2_dev, "buffer queue is empty\n");
> -		return -EINVAL;
> +		return -ENODATA;
>  	}
>  	/* Get the next frame from the buffer queue */
>  	layer->next_frm = layer->cur_frm = list_entry(layer->dma_queue.next,
> diff --git a/drivers/media/platform/davinci/vpif_capture.c b/drivers/media/platform/davinci/vpif_capture.c
> index 52ac5e6..4b04a27 100644
> --- a/drivers/media/platform/davinci/vpif_capture.c
> +++ b/drivers/media/platform/davinci/vpif_capture.c
> @@ -277,7 +277,7 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	if (list_empty(&common->dma_queue)) {
>  		spin_unlock_irqrestore(&common->irqlock, flags);
>  		vpif_dbg(1, debug, "buffer queue is empty\n");
> -		return -EIO;
> +		return -ENODATA;
>  	}
>  
>  	/* Get the next frame from the buffer queue */
> diff --git a/drivers/media/platform/davinci/vpif_display.c b/drivers/media/platform/davinci/vpif_display.c
> index c31bcf1..c5070dc 100644
> --- a/drivers/media/platform/davinci/vpif_display.c
> +++ b/drivers/media/platform/davinci/vpif_display.c
> @@ -239,7 +239,7 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	if (list_empty(&common->dma_queue)) {
>  		spin_unlock_irqrestore(&common->irqlock, flags);
>  		vpif_err("buffer queue is empty\n");
> -		return -EIO;
> +		return -ENODATA;
>  	}
>  
>  	/* Get the next frame from the buffer queue */
> diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
> index 4ff3b6c..3bdfe85 100644
> --- a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
> +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
> @@ -1863,7 +1863,7 @@ static int s5p_mfc_start_streaming(struct vb2_queue *q, unsigned int count)
>  		if (ctx->src_bufs_cnt < ctx->pb_count) {
>  			mfc_err("Need minimum %d OUTPUT buffers\n",
>  					ctx->pb_count);
> -			return -EINVAL;
> +			return -ENODATA;
>  		}
>  	}
>  
> diff --git a/drivers/media/platform/s5p-tv/mixer_video.c b/drivers/media/platform/s5p-tv/mixer_video.c
> index 81b97db..220ec31 100644
> --- a/drivers/media/platform/s5p-tv/mixer_video.c
> +++ b/drivers/media/platform/s5p-tv/mixer_video.c
> @@ -948,7 +948,7 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
>  
>  	if (count == 0) {
>  		mxr_dbg(mdev, "no output buffers queued\n");
> -		return -EINVAL;
> +		return -ENODATA;
>  	}
>  
>  	/* block any changes in output configuration */
> diff --git a/drivers/media/platform/soc_camera/mx2_camera.c b/drivers/media/platform/soc_camera/mx2_camera.c
> index 45a0276..587e3d1 100644
> --- a/drivers/media/platform/soc_camera/mx2_camera.c
> +++ b/drivers/media/platform/soc_camera/mx2_camera.c
> @@ -659,7 +659,7 @@ static int mx2_start_streaming(struct vb2_queue *q, unsigned int count)
>  	unsigned long flags;
>  
>  	if (count < 2)
> -		return -EINVAL;
> +		return -ENODATA;
>  
>  	spin_lock_irqsave(&pcdev->lock, flags);
>  
> diff --git a/drivers/staging/media/davinci_vpfe/vpfe_video.c b/drivers/staging/media/davinci_vpfe/vpfe_video.c
> index 24d98a6..a81b0ab 100644
> --- a/drivers/staging/media/davinci_vpfe/vpfe_video.c
> +++ b/drivers/staging/media/davinci_vpfe/vpfe_video.c
> @@ -1201,6 +1201,8 @@ static int vpfe_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	unsigned long addr;
>  	int ret;
>  
> +	if (count == 0)
> +		return -ENODATA;
>  	ret = mutex_lock_interruptible(&video->lock);
>  	if (ret)
>  		goto streamoff;
>