diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
index ca85420..a700285 100644
--- a/include/media/v4l2-event.h
+++ b/include/media/v4l2-event.h
@@ -222,7 +222,8 @@
 				  struct v4l2_fh *fh,
 				  struct v4l2_event_subscription *sub);
 /**
- * v4l2_src_change_event_subscribe -
+ * v4l2_src_change_event_subscribe - helper function that calls
+ * 	v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE.
  *
  * @fh: pointer to struct v4l2_fh
  * @sub: pointer to &struct v4l2_event_subscription