diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index e0749108840006ffda3965e8dca1d71bb926d889..a75aefef528e6601523344b80438fc70e34dbd9b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -486,6 +486,16 @@ static void edid_fixup_preferred(struct drm_connector *connector,
 	preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
 }
 
+/*
+ * drm_mode_find_dmt - Create a copy of a mode if present in DMT
+ * @dev: Device to duplicate against
+ * @hsize: Mode width
+ * @vsize: Mode height
+ * @fresh: Mode refresh rate
+ *
+ * Walk the DMT mode list looking for a match for the given parameters.
+ * Return a newly allocated copy of the mode, or NULL if not found.
+ */
 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
 					   int hsize, int vsize, int fresh)
 {