media: mc: Fix flags handling when creating pad links

The media_create_pad_link() function doesn't correctly clear reject link
type flags, nor does it set the DATA_LINK flag. It only works because
the MEDIA_LNK_FL_DATA_LINK flag's value is 0.

Fix it by returning an error if any link type flag is set. This doesn't
introduce any regression, as nobody calls the media_create_pad_link()
function with link type flags (easily checked by grepping for the flag
in the source code, there are very few hits).

Set the MEDIA_LNK_FL_DATA_LINK explicitly, which is a no-op that the
compiler will optimize out, but is still useful to make the code more
explicit and easier to understand.

Cc: stable@vger.kernel.org # 6.1
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index a6f28366106fbee6deff563c58e5039433c05819..7839e3f68efa46deb563692303a0a4cd032429c1 100644 (file)
--- a/drivers/media/mc/mc-entity.c
+++ b/drivers/media/mc/mc-entity.c
@@ -1092,6 +1092,11 @@ media_create_pad_link(struct media_entity *source, u16 source_pad,
        struct media_link *link;
        struct media_link *backlink;
 
+       if (flags & MEDIA_LNK_FL_LINK_TYPE)
+               return -EINVAL;
+
+       flags |= MEDIA_LNK_FL_DATA_LINK;
+
        if (WARN_ON(!source || !sink) ||
            WARN_ON(source_pad >= source->num_pads) ||
            WARN_ON(sink_pad >= sink->num_pads))
@@ -1107,7 +1112,7 @@ media_create_pad_link(struct media_entity *source, u16 source_pad,
 
        link->source = &source->pads[source_pad];
        link->sink = &sink->pads[sink_pad];
-       link->flags = flags & ~MEDIA_LNK_FL_INTERFACE_LINK;
+       link->flags = flags;
 
        /* Initialize graph object embedded at the new link */
        media_gobj_create(source->graph_obj.mdev, MEDIA_GRAPH_LINK,