GTMPSC_NTXDESC
sc->sc_nexttx = (ix + 1) % GTMPSC_NTXDESC;
ix = GTMPSC_NTXDESC - 1;
for (i = 0; i < GTMPSC_NTXDESC; i++) {
sc->sc_nexttx = (ix + 1) % GTMPSC_NTXDESC;
sc->sc_lasttx = (sc->sc_lasttx + 1) % GTMPSC_NTXDESC;
sc->sc_lasttx = (sc->sc_lasttx + 1) % GTMPSC_NTXDESC;
(sc->sc_rcvrx + 1) % GTMPSC_NTXDESC;
ix = (ix + 1) % GTMPSC_NTXDESC;
ix = (ix + 1) % GTMPSC_NTXDESC;
gtmpsc_polltx_t tx[GTMPSC_NTXDESC];