AXE_N_TRANSFER
static const struct usb_config axe_config[AXE_N_TRANSFER] = {
axe_config, AXE_N_TRANSFER, sc, &sc->sc_mtx);
usbd_transfer_unsetup(sc->sc_xfer, AXE_N_TRANSFER);
struct usb_xfer *sc_xfer[AXE_N_TRANSFER];