VR_RXCFG
VR_CLRBIT(sc, VR_RXCFG, VR_RXCFG_RX_THRESH);
VR_SETBIT(sc, VR_RXCFG, VR_RXTHRESH_128BYTES);
rxfilt = CSR_READ_1(sc, VR_RXCFG);
CSR_WRITE_1(sc, VR_RXCFG, rxfilt);
CSR_WRITE_1(sc, VR_RXCFG, rxfilt);