UKBD_INTR_DT_0
[UKBD_INTR_DT_0] = {
usbd_xfer_set_interval(sc->sc_xfer[UKBD_INTR_DT_0], rate);
usbd_transfer_start(sc->sc_xfer[UKBD_INTR_DT_0]);
usbd_transfer_stop(sc->sc_xfer[UKBD_INTR_DT_0]);
usbd_transfer_start(sc->sc_xfer[UKBD_INTR_DT_0]);