WMREG_FFLT_DBG
mac_reg = CSR_READ(sc, WMREG_FFLT_DBG);
CSR_WRITE(sc, WMREG_FFLT_DBG, mac_reg);
reg = CSR_READ(sc, WMREG_FFLT_DBG);
CSR_WRITE(sc, WMREG_FFLT_DBG, reg);