ET_MII_CMD
CSR_WRITE_4(sc, ET_MII_CMD, 0);
CSR_WRITE_4(sc, ET_MII_CMD, ET_MII_CMD_READ);
CSR_WRITE_4(sc, ET_MII_CMD, 0);
CSR_WRITE_4(sc, ET_MII_CMD, 0);
CSR_WRITE_4(sc, ET_MII_CMD, 0);