如何编译在关闭接收RX线程情况下的系统？

#ifndef LWIP_NO_RX_THREAD
rt_err_t eth_device_ready(struct eth_device* dev)
{
    if (dev->netif)
        /* post message to Ethernet thread */
        return rt_mb_send(ð_rx_thread_mb, (rt_uint32_t)dev);
    else
        return ERR_OK; /* netif is not initialized yet, just return. */
}