WMREG_RDT
CSR_WRITE(l, WMREG_RDT, 0);
CSR_WRITE(l, WMREG_RDT, l->rx);
CSR_WRITE(l, WMREG_RDT, l->rx);
CSR_WRITE(sc, WMREG_RDT(qid), 0);
CSR_WRITE(sc, WMREG_RDT(qid), 0);
rxq->rxq_rdt_reg = WMREG_RDT(wmq->wmq_id);