Re: [PATCH v7 09/12] media: rkvdec: Add get_image_fmt ops

[Hans Verkuil <hverkuil@xs4all.nl>]

On 25/02/2025 10:40, Sebastian Fricke wrote:
> From: Jonas Karlman <jonas@kwiboo.se>
> 
> Add support for a get_image_fmt() ops that returns the required image
> format.
> 
> The CAPTURE format is reset when the required image format changes and
> the buffer queue is not busy.
> 
> Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
> Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> Tested-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
> Tested-by: Christopher Obbard <chris.obbard@collabora.com>
> ---
>  drivers/staging/media/rkvdec/rkvdec.c | 49 +++++++++++++++++++++++++++++++++--
>  drivers/staging/media/rkvdec/rkvdec.h |  2 ++
>  2 files changed, 49 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c
> index 70154948b4e32e2c439f259b0f1e1bbc8b52b063..5394079509305c619f1d0c1f542bfc409317c3b7 100644
> --- a/drivers/staging/media/rkvdec/rkvdec.c
> +++ b/drivers/staging/media/rkvdec/rkvdec.c
> @@ -111,15 +111,60 @@ static int rkvdec_try_ctrl(struct v4l2_ctrl *ctrl)
>  {
>  	struct rkvdec_ctx *ctx = container_of(ctrl->handler, struct rkvdec_ctx, ctrl_hdl);
>  	const struct rkvdec_coded_fmt_desc *desc = ctx->coded_fmt_desc;
> +	struct v4l2_pix_format_mplane *pix_mp = &ctx->decoded_fmt.fmt.pix_mp;
> +	enum rkvdec_image_fmt image_fmt;
> +	struct vb2_queue *vq;
> +	int ret;
> +
> +	if (desc->ops->try_ctrl) {
> +		ret = desc->ops->try_ctrl(ctx, ctrl);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (!desc->ops->get_image_fmt)
> +		return 0;
>  
> -	if (desc->ops->try_ctrl)
> -		return desc->ops->try_ctrl(ctx, ctrl);
> +	image_fmt = desc->ops->get_image_fmt(ctx, ctrl);
> +	if (ctx->image_fmt == image_fmt)
> +		return 0;
> +
> +	if (rkvdec_is_valid_fmt(ctx, pix_mp->pixelformat, image_fmt))
> +		return 0;
> +
> +	/* format change not allowed when queue is busy */
> +	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx,
> +			     V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
> +	if (vb2_is_busy(vq))
> +		return -EINVAL;

This makes no sense to me. This just tries a control, and that should just
work, regardless of vb2_is_busy(). It's a 'try', so you are not actually
changing anything.

> +
> +	return 0;
> +}
> +
> +static int rkvdec_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct rkvdec_ctx *ctx = container_of(ctrl->handler, struct rkvdec_ctx, ctrl_hdl);
> +	const struct rkvdec_coded_fmt_desc *desc = ctx->coded_fmt_desc;
> +	struct v4l2_pix_format_mplane *pix_mp = &ctx->decoded_fmt.fmt.pix_mp;
> +	enum rkvdec_image_fmt image_fmt;
> +
> +	if (!desc->ops->get_image_fmt)
> +		return 0;
> +
> +	image_fmt = desc->ops->get_image_fmt(ctx, ctrl);
> +	if (ctx->image_fmt == image_fmt)
> +		return 0;

If you really can't set a control when the queue is busy, then that should
be tested here, not in try_ctrl. And then you return -EBUSY.

Am I missing something here?

Regards,

	Hans

> +
> +	ctx->image_fmt = image_fmt;
> +	if (!rkvdec_is_valid_fmt(ctx, pix_mp->pixelformat, ctx->image_fmt))
> +		rkvdec_reset_decoded_fmt(ctx);
>  
>  	return 0;
>  }
>  
>  static const struct v4l2_ctrl_ops rkvdec_ctrl_ops = {
>  	.try_ctrl = rkvdec_try_ctrl,
> +	.s_ctrl = rkvdec_s_ctrl,
>  };
>  
>  static const struct rkvdec_ctrl_desc rkvdec_h264_ctrl_descs[] = {
> diff --git a/drivers/staging/media/rkvdec/rkvdec.h b/drivers/staging/media/rkvdec/rkvdec.h
> index 6f8cf50c5d99aad2f52e321f54f3ca17166ddf98..e466a2753ccfc13738e0a672bc578e521af2c3f2 100644
> --- a/drivers/staging/media/rkvdec/rkvdec.h
> +++ b/drivers/staging/media/rkvdec/rkvdec.h
> @@ -73,6 +73,8 @@ struct rkvdec_coded_fmt_ops {
>  		     struct vb2_v4l2_buffer *dst_buf,
>  		     enum vb2_buffer_state result);
>  	int (*try_ctrl)(struct rkvdec_ctx *ctx, struct v4l2_ctrl *ctrl);
> +	enum rkvdec_image_fmt (*get_image_fmt)(struct rkvdec_ctx *ctx,
> +					       struct v4l2_ctrl *ctrl);
>  };
>  
>  enum rkvdec_image_fmt {
>