---

yaml
---
r: 354707
b: refs/heads/master
c: f6cced1
h: refs/heads/master
i:
  354705: 9f29f45
  354703: 604d891
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ad493e5e580546e6c3024b76a41535476da1546a
+refs/heads/master: f6cced1a08b475c5ac946823bb057714be7af4f6

trunk/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)