diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 53acc6756ee0310017ccc6ef2255c7ef55c2e63e..847048dee048e89a565e2dfaaf31801d69284ac3 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1977,9 +1977,11 @@ int drm_mode_convert_umode(struct drm_device *dev,
 	case DRM_MODE_FLAG_PIC_AR_256_135:
 		out->picture_aspect_ratio = HDMI_PICTURE_ASPECT_256_135;
 		break;
-	default:
+	case DRM_MODE_FLAG_PIC_AR_NONE:
 		out->picture_aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
 		break;
+	default:
+		return -EINVAL;
 	}
 
 	out->status = drm_mode_validate_driver(dev, out);