WMREG_TDT
CSR_WRITE(l, WMREG_TDT, 0);
CSR_WRITE(l, WMREG_TDT, 0);
reg = CSR_READ(sc, WMREG_TDT(wmq->wmq_id));
device_printf(sc->sc_dev, "TDT0: %08x\n", CSR_READ(sc, WMREG_TDT(0)));
CSR_WRITE(sc, WMREG_TDT(0), txq->txq_next);
CSR_WRITE(sc, WMREG_TDT(0), 0);
if (CSR_READ(sc, WMREG_TDT(0)) == CSR_READ(sc, WMREG_TDH(0)) &&
CSR_WRITE(sc, WMREG_TDT(qid), 0);
txq->txq_tdt_reg = WMREG_TDT(wmq->wmq_id);