TXLD
np->cur_tx_copy->control = TXIC | TXLD | TXFD | CRCEnable | PADEnable;
next->control = TXIC | TXLD | CRCEnable | PADEnable;
np->cur_tx_copy->control = TXIC | TXLD | TXFD | CRCEnable | PADEnable;
if (!(tx_control & TXLD)) { /* this pkt is combined by two tx descriptors */
if (np->cur_tx->control & TXLD) {