USB: Add a sysfs file to show LTM capabilities.
USB 3.0 devices can optionally support Latency Tolerance Messaging
(LTM). Add a new sysfs file in the device directory to show whether a
device is LTM capable. This file will be present for both USB 2.0 and
USB 3.0 devices.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index f29831b..f8506ed 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -636,6 +636,14 @@
extern int usb_disable_ltm(struct usb_device *udev);
extern void usb_enable_ltm(struct usb_device *udev);
+static inline bool usb_device_supports_ltm(struct usb_device *udev)
+{
+ if (udev->speed != USB_SPEED_SUPER || !udev->bos || !udev->bos->ss_cap)
+ return false;
+ return udev->bos->ss_cap->bmAttributes & USB_LTM_SUPPORT;
+}
+
+
/*-------------------------------------------------------------------------*/
/* for drivers using iso endpoints */