BCE_FILT_CTL
bus_space_write_4(sc->bce_btag, sc->bce_bhandle, BCE_FILT_CTL, 0);
bus_space_write_4(sc->bce_btag, sc->bce_bhandle, BCE_FILT_CTL,
bus_space_read_4(sc->bce_btag, sc->bce_bhandle, BCE_FILT_CTL) | 1);
bus_space_write_4(sc->bce_btag, sc->bce_bhandle, BCE_FILT_CTL,
BCE_FILT_CTL);