Hi Kieran,
On Wed, May 17, 2017 at 04:38:14PM +0100, Kieran Bingham wrote:
> From: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
> Return NULL, if a null entity is parsed for it's v4l2_subdev
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
> include/media/v4l2-subdev.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index 5f1669c45642..72d7f28f38dc 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -829,7 +829,7 @@ struct v4l2_subdev {
> };
>
> #define media_entity_to_v4l2_subdev(ent) \
> - container_of(ent, struct v4l2_subdev, entity)
> + (ent ? container_of(ent, struct v4l2_subdev, entity) : NULL)
> #define vdev_to_v4l2_subdev(vdev) \
> ((struct v4l2_subdev *)video_get_drvdata(vdev))
>
The problem with this is that ent is now referenced twice. If the ent macro
argument has side effect, this would introduce bugs. It's unlikely, but
worth avoiding. Either use a macro or a function.
I think I'd use function for there's little use for supporting for const and
non-const arguments presumably. A simple static inline function should do.
--
Regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx
