_HME_NDESC
sc->sc_rb.rb_ntbuf = _HME_NDESC;
sc->sc_rb.rb_nrbuf = _HME_NDESC;
bus_space_write_4(t, etx, HME_ETXI_RSIZE, _HME_NDESC / 16 - 1);
switch (_HME_NDESC /*XXX*/) {