SIS_CMDSTS_MORE
if (cur_tx->sis_ctl & SIS_CMDSTS_MORE)
f->sis_ctl = SIS_CMDSTS_MORE | segs[i].ds_len;
ld->sis_tx_list[cur].sis_ctl &= ~SIS_CMDSTS_MORE;
#define SIS_LASTDESC(x) (!((x)->sis_ctl & SIS_CMDSTS_MORE)))