SL_CUR_TXBUF
while (SL_CUR_TXBUF(sc) == NULL) { /* SL_CUR_TXBUF(x) = x->sln_bufdata.sln_tx_buf[x->sln_bufdata.cur_tx] */
SL_CUR_TXBUF(sc) = m_head;
BPF_MTAP(ifp, SL_CUR_TXBUF(sc));
vtophys(mtod(SL_CUR_TXBUF(sc), caddr_t)));
if ((SL_CUR_TXBUF(sc)->m_pkthdr.len < 60) && (!sc->txenablepad)) {
} else if (SL_CUR_TXBUF(sc)->m_pkthdr.len < 100)
SLN_WRITE_4(sc, (entry * 4) + SL_TSD0, SL_CUR_TXBUF(sc)->m_pkthdr.len);
else if (SL_CUR_TXBUF(sc)->m_pkthdr.len < 300)
SLN_WRITE_4(sc, (entry * 4) + SL_TSD0, 0x30000 | SL_CUR_TXBUF(sc)->m_pkthdr.len);
SLN_WRITE_4(sc, (entry * 4) + SL_TSD0, 0x50000 | SL_CUR_TXBUF(sc)->m_pkthdr.len);
if (SL_CUR_TXBUF(sc) != NULL)