Re: [PATCH v13 01/22] media: mc: Add INTERNAL pad flag

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Fallback logic in `media_entity_get_fwnode_pad()` improperly returns internal pads for fwnode endpoints.
--

commit a0ac801b415beb48f5c9da940609a2ea7d38e0d3
Author: Sakari Ailus <sakari.ailus@linux.intel.com>

media: mc: Add INTERNAL pad flag

This commit introduces a new MEDIA_PAD_FL_INTERNAL flag for media pads
to indicate routing endpoints that originate within the entity. It also
adds safeguards to prevent creating links to internal pads and initializing
source pads as internal.

> diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
> index 3fa0bc687851b..7938f785e2e3c 100644
> --- a/drivers/media/mc/mc-entity.c
> +++ b/drivers/media/mc/mc-entity.c
[ ... ]
> @@ -1148,6 +1154,9 @@ media_create_pad_link(struct media_entity *source, u16 source_pad,
>  		return -EINVAL;
>  	if (WARN_ON(!(sink->pads[sink_pad].flags & MEDIA_PAD_FL_SINK)))
>  		return -EINVAL;
> +	if (WARN_ON(source->pads[source_pad].flags & MEDIA_PAD_FL_INTERNAL) ||
> +	    WARN_ON(sink->pads[sink_pad].flags & MEDIA_PAD_FL_INTERNAL))
> +		return -EINVAL;

[Severity: High]
With this new safeguard for internal pads, will media_entity_get_fwnode_pad()
incorrectly return an internal pad and later trigger this warning?

If a driver lacks the get_fwnode_pad operation and direction_flags is passed
as MEDIA_PAD_FL_SINK, the fallback logic will match an internal pad because
it also has the MEDIA_PAD_FL_SINK bit set:

drivers/media/mc/mc-entity.c:media_entity_get_fwnode_pad() {
    ...
	if (!entity->ops || !entity->ops->get_fwnode_pad) {
		for (i = 0; i < entity->num_pads; i++) {
			if (entity->pads[i].flags & direction_flags)
				return i;
		}
    ...
}

Should the fallback logic be updated to explicitly skip pads with the
MEDIA_PAD_FL_INTERNAL flag?

>  
>  	link = media_add_link(&source->links);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260604-gmsl2-3_serdes-v13-0-9d8a4919983b@analog.com?part=1