diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index d6d74bcfe1839e9d89280182164d3e9a9c659ce6..0c003d8174937ba47afa097d6a54b4fb8adce31d 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -44,6 +44,15 @@ struct media_pad {
 	unsigned long flags;		/* Pad flags (MEDIA_PAD_FL_*) */
 };
 
+/**
+ * struct media_entity_operations - Media entity operations
+ * @link_setup:		Notify the entity of link changes. The operation can
+ *			return an error, in which case link setup will be
+ *			cancelled. Optional.
+ * @link_validate:	Return whether a link is valid from the entity point of
+ *			view. The media_entity_pipeline_start() function
+ *			validates all links by calling this operation. Optional.
+ */
 struct media_entity_operations {
 	int (*link_setup)(struct media_entity *entity,
 			  const struct media_pad *local,