usbd_do_request
error = usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, &val);
return (usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, NULL));
return (usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, buf));
if ((error = usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, NULL))
return (usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, NULL));
error = usbd_do_request(sc->sc_udev, &sc->sc_mtx, &req, &tmp);