dz_read2
while ((c = dz_read2(sc, sc->sc_dr.dr_rbuf)) & DZ_RBUF_DATA_VALID) {
csr = dz_read2(sc, sc->sc_dr.dr_csr);
tcr = dz_read2(sc, sc->sc_dr.dr_tcrw);
state = dz_read2(sc, sc->sc_dr.dr_tcrw) & 255;
tmp = dz_read2(sc, sc->sc_dr.dr_tcrw) & 255;
csr = dz_read2(sc, sc->sc_dr.dr_csr);