Re: [PATCH 8/8] media: cedrus: Add support for V4L2_DEC_CMD_FLUSH

[Boris Brezillon]

On Thu, 22 Aug 2019 21:45:00 +0200
Jernej Skrabec <jernej.skrabec@xxxxxxxx> wrote:

> This command is useful for explicitly flushing last decoded frame.
> 
> Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>

> ---
>  .../staging/media/sunxi/cedrus/cedrus_video.c | 34 +++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_video.c b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
> index 5153b2bba21e..9eae69d5741c 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_video.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
> @@ -331,6 +331,37 @@ static int cedrus_s_fmt_vid_out(struct file *file, void *priv,
>  	return 0;
>  }
>  
> +static int cedrus_try_decoder_cmd(struct file *file, void *fh,
> +				  struct v4l2_decoder_cmd *dc)
> +{
> +	if (dc->cmd != V4L2_DEC_CMD_FLUSH)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int cedrus_decoder_cmd(struct file *file, void *fh,
> +			      struct v4l2_decoder_cmd *dc)
> +{
> +	struct cedrus_ctx *ctx = cedrus_file2ctx(file);
> +	struct vb2_v4l2_buffer *out_vb, *cap_vb;
> +	int ret;
> +
> +	ret = cedrus_try_decoder_cmd(file, fh, dc);
> +	if (ret < 0)
> +		return ret;

Not directly related to this patch, but it seems most drivers
implementing ->vdioc_decoder_cmd() call ->vidioc_try_decoder_cmd()
internally to make sure the cmd is supported. Maybe something
we could automate at the v4l2-ioctl.c level.