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-rw-r--r--drivers/usb/core/hub.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c8e0704c6e5..100e08f8a02 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -177,6 +177,21 @@ static struct usb_hub *hdev_to_hub(struct usb_device *hdev)
return usb_get_intfdata(hdev->actconfig->interface[0]);
}
+static int usb_device_supports_lpm(struct usb_device *udev)
+{
+ /* USB 2.1 (and greater) devices indicate LPM support through
+ * their USB 2.0 Extended Capabilities BOS descriptor.
+ */
+ if (udev->speed == USB_SPEED_HIGH) {
+ if (udev->bos->ext_cap &&
+ (USB_LPM_SUPPORT &
+ le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
+ return 1;
+ return 0;
+ }
+ return 0;
+}
+
/* USB 2.0 spec Section 11.24.4.5 */
static int get_hub_descriptor(struct usb_device *hdev, void *data)
{
@@ -3211,11 +3226,8 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
retval = usb_get_bos_descriptor(udev);
- if (!retval) {
- if (udev->bos->ext_cap && (USB_LPM_SUPPORT &
- le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
- udev->lpm_capable = 1;
- }
+ if (!retval)
+ udev->lpm_capable = usb_device_supports_lpm(udev);
}
retval = 0;