GUS_DMAOUT_ACTIVE
sc->sc_flags |= GUS_DMAOUT_ACTIVE;
sc->sc_flags &= ~(GUS_DMAOUT_ACTIVE|GUS_LOCKED);
sc->sc_flags &= ~(GUS_OPEN|GUS_LOCKED|GUS_DMAOUT_ACTIVE|GUS_DMAIN_ACTIVE);
sc->sc_flags &= ~GUS_DMAOUT_ACTIVE; /* pending DMA is done */