btusb_submit_bulk_urb
err = btusb_submit_bulk_urb(hdev, GFP_KERNEL);
btusb_submit_bulk_urb(hdev, GFP_KERNEL);
err = btusb_submit_bulk_urb(hdev, GFP_NOIO);
btusb_submit_bulk_urb(hdev, GFP_NOIO);