MT_WF_RFCR
sc->sc_rxfilter = mwx_read(sc, MT_WF_RFCR(0));
mwx_set(sc, MT_WF_RFCR(0), MT_WF_RFCR_DROP_OTHER_BEACON);
mwx_clear(sc, MT_WF_RFCR(0), MT_WF_RFCR_DROP_OTHER_BEACON);
mwx_write(sc, MT_WF_RFCR(0), sc->sc_rxfilter);