spc_intr
dio_intr_establish(spc_intr, (void *)sc, da->da_ipl, ISRPRI_BIO);
isrlink_autovec(spc_intr, (void *)sc, ma->ma_ilvl, ISRPRI_BIO);
if (intio_intr_establish(ia->ia_intr, "spc", spc_intr, sc))
spc_intr(sc);
int spc_intr(void *);
spc_intr, &sc->sc_spc);