MTD_RXD_OWNER
sc->desc[i].stat = MTD_RXD_OWNER;
for (; !(sc->desc[sc->cur_rx].stat & MTD_RXD_OWNER);) {
sc->desc[sc->cur_rx].stat = MTD_RXD_OWNER;
sc->desc[sc->cur_rx].stat = MTD_RXD_OWNER;
sc->desc[sc->cur_rx].stat = MTD_RXD_OWNER;