AUICH_GCTRL
control = bus_space_read_4(sc->iot, sc->aud_ioh, AUICH_GCTRL);
bus_space_write_4(sc->iot, sc->aud_ioh, AUICH_GCTRL, control);
control = bus_space_read_4(sc->iot, sc->aud_ioh, AUICH_GCTRL);
bus_space_write_4(sc->iot, sc->aud_ioh, AUICH_GCTRL, control);