TN40_SHORT_PACKET_SIZE
if (skb->len < TN40_SHORT_PACKET_SIZE)
if (pkt_len < TN40_SHORT_PACKET_SIZE) {
txdd->length = cpu_to_le16(TN40_SHORT_PACKET_SIZE);
pbl->len = cpu_to_le32(TN40_SHORT_PACKET_SIZE - pkt_len);