MAVB_CONTROL
control = bus_space_read_8(sc->sc_st, sc->sc_sh, MAVB_CONTROL);
bus_space_write_8(sc->sc_st, sc->sc_sh, MAVB_CONTROL, control);
control = bus_space_read_8(sc->sc_st, sc->sc_sh, MAVB_CONTROL);
bus_space_write_8(sc->sc_st, sc->sc_sh, MAVB_CONTROL,
bus_space_write_8(sc->sc_st, sc->sc_sh, MAVB_CONTROL, 0);