diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c4073666f1ca916bf9881a5d2665d1210c1b39cc..71651ca7a8b1bf5bfa8f695b6dd1bc6ec626d160 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -632,7 +632,7 @@ enum intel_pch {
 	PCH_KBP,        /* Kaby Lake PCH */
 	PCH_CNP,        /* Cannon Lake PCH */
 	PCH_ICP,	/* Ice Lake PCH */
-	PCH_NOP,
+	PCH_NOP,	/* PCH without south display */
 };
 
 enum intel_sbi_destination {