MVXPE_TX_RING_MEM_PA
KASSERT(MVXPE_TX_RING_MEM_PA(sc, q) != 0);
MVXPE_WRITE(sc, MVXPE_PTXDQA(q), MVXPE_TX_RING_MEM_PA(sc, q));
KASSERT(MVXPE_READ(sc, MVXPE_PTXDQA(q)) == MVXPE_TX_RING_MEM_PA(sc, q));