diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index 78a53c8b17898cb8608662b3343a15c082e64b84..41296935ef117e81267826f682a01f3f4ba008e1 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -397,8 +397,11 @@ intel_panel_detect(struct drm_i915_private *dev_priv)
 
 /**
  * scale - scale values from one range to another
- *
  * @source_val: value in range [@source_min..@source_max]
+ * @source_min: minimum legal value for @source_val
+ * @source_max: maximum legal value for @source_val
+ * @target_min: corresponding target value for @source_min
+ * @target_max: corresponding target value for @source_max
  *
  * Return @source_val in range [@source_min..@source_max] scaled to range
  * [@target_min..@target_max].