diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 280433d808871f799782d5ce1d7b53993275fc1c..9a15b26944ec9a3c73c6d948ce0f508418021d39 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -67,6 +67,7 @@ static void usb_port_device_release(struct device *dev)
 {
 	struct usb_port *port_dev = to_usb_port(dev);
 
+	dev_pm_qos_hide_flags(dev);
 	usb_acpi_unregister_power_resources(dev);
 	kfree(port_dev);
 }
@@ -176,7 +177,15 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 		goto error_register;
 
 	pm_runtime_set_active(&port_dev->dev);
-	pm_runtime_enable(&port_dev->dev);
+
+	/* It would be dangerous if user space couldn't
+	 * prevent usb device from being powered off. So don't
+	 * enable port runtime pm if failed to expose port's pm qos.
+	 */
+	if (!dev_pm_qos_expose_flags(&port_dev->dev,
+			PM_QOS_FLAG_NO_POWER_OFF))
+		pm_runtime_enable(&port_dev->dev);
+
 
 	retval = usb_acpi_register_power_resources(&port_dev->dev);
 	if (retval && retval != -ENODEV)