WMREG_TDH
CSR_WRITE(l, WMREG_TDH, 0);
reg = CSR_READ(sc, WMREG_TDH(wmq->wmq_id));
if (CSR_READ(sc, WMREG_TDT(0)) == CSR_READ(sc, WMREG_TDH(0)) &&
CSR_WRITE(sc, WMREG_TDH(qid), 0);