Re: [PATCH v7 09/14] media: v4l2-subdev: Always call get_fmt() if set_fmt() is unavailable

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

On Fri, Aug 07, 2026 at 03:24:04PM +0300, Sakari Ailus wrote:
> Many drivers implement set_fmt() pad op that simply returns the format
> just as get_fmt() would do, usually because the driver only supports a
> single one. As a driver should always implement set_fmt() either on its
> own or via get_fmt(), call get_fmt() in case set_fmt() isn't implemented
> by the driver. This allows removing a fair amount of boilerplate code as
> well as ensures that set_fmt() works whenever get_fmt() does.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index f53bac995822..58e50d9442e7 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -260,8 +260,19 @@ static int call_set_fmt(struct v4l2_subdev *sd,
>  			struct v4l2_subdev_state *state,
>  			struct v4l2_subdev_format *format)
>  {
> -	return do_subdev_call(sd, check_format(sd, state, format), pad, set_fmt,
> -			      state, format);
> +	int ret;
> +
> +	if (!sd->ops->pad->set_fmt && !sd->ops->pad->get_fmt)
> +		return -ENOIOCTLCMD;
> +
> +	ret = check_format(sd, state, format);
> +	if (ret)
> +		return ret;
> +
> +	if (sd->ops->pad->set_fmt)
> +		return sd->ops->pad->set_fmt(sd, state, format);
> +
> +	return sd->ops->pad->get_fmt(sd, state, format);
>  }
>  
>  static int check_which_pad_state(struct v4l2_subdev *sd,

-- 
Regards,

Laurent Pinchart