VR_NEXTTX
firsttx = VR_NEXTTX(sc->vr_txlast);
nexttx = VR_NEXTTX(sc->vr_txlast);
d->vr_next = htole32(VR_CDTXADDR(sc, VR_NEXTTX(i)));
CSR_WRITE_4(sc, VR_TXADDR, VR_CDTXADDR(sc, VR_NEXTTX(sc->vr_txlast)));
i = VR_NEXTTX(i), sc->vr_txpending--) {