ZYX_MAX_RXBUFSZ
usbd_setup_xfer(xfer, data, NULL, ZYX_MAX_RXBUFSZ, USBD_SHORT_XFER_OK,
usbd_setup_xfer(data->xfer, data, NULL, ZYX_MAX_RXBUFSZ,
ZYX_MAX_RXBUFSZ, 0, 0, &data->xfer);