Re: [PATCH for v5.3] v4l2-subdev: fix regression in check_pad()

["Niklas Söderlund" <niklas.soderlund@ragnatech.se>]

Hi Hans,

Thanks for your work.

On 2019-06-29 12:00:24 +0200, Hans Verkuil wrote:
> sd->entity.graph_obj.mdev can be NULL when this function is called, and
> that breaks existing drivers (rcar-vin, but probably others as well).
> 
> Check if sd->entity.num_pads is non-zero instead since that doesn't depend
> on mdev.
> 
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Reported-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Fixes: a8fa55078a77 ("media: v4l2-subdev: Verify arguments in v4l2_subdev_call()")

This fixes my problem,

Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> ---
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index 21fb90d66bfc..bc32fc1e0c0b 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -124,16 +124,11 @@ static inline int check_which(__u32 which)
>  static inline int check_pad(struct v4l2_subdev *sd, __u32 pad)
>  {
>  #if defined(CONFIG_MEDIA_CONTROLLER)
> -	if (sd->entity.graph_obj.mdev) {
> -		if (pad >= sd->entity.num_pads)
> -			return -EINVAL;
> -		return 0;
> -	}
> +	if (sd->entity.num_pads)
> +		return pad >= sd->entity.num_pads ? -EINVAL : 0;
>  #endif
>  	/* allow pad 0 on subdevices not registered as media entities */
> -	if (pad > 0)
> -		return -EINVAL;
> -	return 0;
> +	return pad ? -EINVAL : 0;
>  }
> 
>  static int check_cfg(__u32 which, struct v4l2_subdev_pad_config *cfg)

-- 
Regards,
Niklas Söderlund