media: mc: Check pad flag validity

Check the validity of pad flags on entity init. Exactly one of the flags
must be set.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/mc/mc-entity.c

@@ -197,6 +197,7 @@ int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 	struct media_device *mdev = entity->graph_obj.mdev;
 	struct media_pad *iter;
 	unsigned int i = 0;
+	int ret = 0;
 
 	if (num_pads >= MEDIA_ENTITY_MAX_PADS)
 		return -E2BIG;
@@ -210,15 +211,27 @@ int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
 	media_entity_for_each_pad(entity, iter) {
 		iter->entity = entity;
 		iter->index = i++;
+
+		if (hweight32(iter->flags & (MEDIA_PAD_FL_SINK |
+					     MEDIA_PAD_FL_SOURCE)) != 1) {
+			ret = -EINVAL;
+			break;
+		}
+
 		if (mdev)
 			media_gobj_create(mdev, MEDIA_GRAPH_PAD,
 					  &iter->graph_obj);
 	}
 
+	if (ret && mdev) {
+		media_entity_for_each_pad(entity, iter)
+			media_gobj_destroy(&iter->graph_obj);
+	}
+
 	if (mdev)
 		mutex_unlock(&mdev->graph_mutex);
 
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(media_entity_pads_init);