PORT100_FRAME_TAIL_LEN
dev->skb_tailroom = PORT100_FRAME_TAIL_LEN;
PORT100_FRAME_TAIL_LEN;
skb_put(skb, PORT100_FRAME_TAIL_LEN);
skb_trim(resp, resp->len - PORT100_FRAME_TAIL_LEN);
PORT100_FRAME_TAIL_LEN;