diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
index 5611a2e4ddf0c9c334cd81d06b011a7715593312..2d9b459bd890c46a47a386fd7b8f8c9748cae720 100644
--- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt
@@ -38,6 +38,8 @@ Optional properties:
 	mode;
  - mediatek,syscon-wakeup : phandle to syscon used to access USB wakeup
 	control register, it depends on "mediatek,wakeup-src".
+ - mediatek,u3p-dis-msk : mask to disable u3ports, bit0 for u3port0,
+	bit1 for u3port1, ... etc;
  - vbus-supply : reference to the VBUS regulator;
  - usb3-lpm-capable : supports USB3.0 LPM
  - pinctrl-names : a pinctrl state named "default" must be defined