Re: [PATCH v6 08/16] media: v4l2-subdev: Move op check to sub-device op wrappers

[Frank Li <Frank.li@oss.nxp.com>]

On Wed, Jul 01, 2026 at 03:26:25PM +0300, Sakari Ailus wrote:
> In anticipation of performing work for sub-device operation when the
> driver doesn't implement one, move the check of operation existence to the
> wrapper itself.
>
> No functional change intended.
>
> 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. The arguments to set_fmt() and get_fmt() are about to get
> differentiated so call get_fmt() always if set_fmt() isn't supported by
> the driver. This avoids changing drivers now and allows removing
> boilerplate code from existing drivers.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>  drivers/media/v4l2-core/v4l2-subdev.c | 117 ++++++++++++++++++--------
>  include/media/v4l2-subdev.h           |   6 +-
>  2 files changed, 84 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 070a9e607fe3..86be4d51c9a5 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -244,20 +244,24 @@ static inline int check_format(struct v4l2_subdev *sd,
>  	       check_state(sd, state, format->which, format->pad, format->stream);
>  }
>
...
>
> -	return check_which(code->which) ? : check_pad(sd, code->pad) ? :
> -	       check_state(sd, state, code->which, code->pad, code->stream) ? :
> -	       sd->ops->pad->enum_mbus_code(sd, state, code);
> +	/*
> +	 * FIXME: Convert the check below to use the ternary operator once
> +	 * smatch can handle it.
> +	 */
> +	return do_subdev_call(sd,
> +			      ({
> +				      int ret = check_which(code->which);
> +				      if (!ret)
> +					      ret = check_pad(sd, code->pad);
> +				      if (!ret)
> +					      ret = check_state(sd, state, code->which,
> +								code->pad, code->stream);
> +				      ret;
> +			      }), pad, enum_mbus_code, state, code);
>  }
>
>  static int call_enum_frame_size(struct v4l2_subdev *sd,
> @@ -279,9 +294,20 @@ static int call_enum_frame_size(struct v4l2_subdev *sd,
>  	if (!fse)
>  		return -EINVAL;
>
> -	return check_which(fse->which) ? : check_pad(sd, fse->pad) ? :
> -	       check_state(sd, state, fse->which, fse->pad, fse->stream) ? :
> -	       sd->ops->pad->enum_frame_size(sd, state, fse);
> +	/*
> +	 * FIXME: Convert the check below to use the ternary operator once
> +	 * smatch can handle it.
> +	 */
> +	return do_subdev_call(sd,
> +			      ({
> +				      int ret = check_which(fse->which);
> +				      if (!ret)
> +					      ret = check_pad(sd, fse->pad);
> +				      if (!ret)
> +					      ret = check_state(sd, state, fse->which,
> +								fse->pad, fse->stream);
> +				      ret;
> +			      }), pad, enum_frame_size, state, fse);

>  }
>
>  static int call_enum_frame_interval(struct v4l2_subdev *sd,
> @@ -291,9 +317,20 @@ static int call_enum_frame_interval(struct v4l2_subdev *sd,
>  	if (!fie)
>  		return -EINVAL;
>
> -	return check_which(fie->which) ? : check_pad(sd, fie->pad) ? :
> -	       check_state(sd, state, fie->which, fie->pad, fie->stream) ? :
> -	       sd->ops->pad->enum_frame_interval(sd, state, fie);
> +	/*
> +	 * FIXME: Convert the check below to use the ternary operator once
> +	 * smatch can handle it.
> +	 */
> +	return do_subdev_call(sd,
> +			      ({
> +				      int ret = check_which(fie->which);
> +				      if (!ret)
> +					      ret = check_pad(sd, fie->pad);
> +				      if (!ret)
> +					      ret = check_state(sd, state, fie->which,
> +								fie->pad, fie->stream);
> +				      ret;
> +			      }), pad, enum_frame_interval, state, fie);

look like similar with above check logic, can you use helper funciton
or macro to reduce duplicate and easy to read.

Frank