AR_PIPE_RX_INTR
ed = usbd_get_endpoint_descriptor(usc->sc_iface, AR_PIPE_RX_INTR);
error = usbd_open_pipe_intr(usc->sc_iface, AR_PIPE_RX_INTR,
AR_PIPE_TX_INTR, AR_PIPE_RX_INTR, &usc->ep_ctrl);