MAX_SINGLE_PACKET_SIZE
netdev->max_mtu = MAX_SINGLE_PACKET_SIZE;
dev->rx_urb_size = MAX_SINGLE_PACKET_SIZE;
dev->net->max_mtu = MAX_SINGLE_PACKET_SIZE;
if (unlikely(size > (MAX_SINGLE_PACKET_SIZE + ETH_HLEN + 12))) {
dev->rx_urb_size = MAX_SINGLE_PACKET_SIZE;