+int usb_disable_ltm(struct usb_device *udev)
+{
+ struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
+ /* Check if the roothub and device supports LTM. */
+ if (!usb_device_supports_ltm(hcd->self.root_hub) ||
+ !usb_device_supports_ltm(udev))
+ return 0;
+
+ /* Clear Feature LTM Enable can only be sent if the device is
+ * configured.
+ */
+ if (!udev->actconfig)
+ return 0;
+
+ return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+ USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
+ USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
+ USB_CTRL_SET_TIMEOUT);
+}
+EXPORT_SYMBOL_GPL(usb_disable_ltm);
+
+void usb_enable_ltm(struct usb_device *udev)
+{
+ struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
+ /* Check if the roothub and device supports LTM. */
+ if (!usb_device_supports_ltm(hcd->self.root_hub) ||
+ !usb_device_supports_ltm(udev))
+ return;
+
+ /* Set Feature LTM Enable can only be sent if the device is
+ * configured.
+ */
+ if (!udev->actconfig)
+ return;
+
+ usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+ USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
+ USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
+ USB_CTRL_SET_TIMEOUT);
+}
+EXPORT_SYMBOL_GPL(usb_enable_ltm);
+