ACXREG_PHY_CTRL
CSR_WRITE_4(sc, ACXREG_PHY_CTRL, ACXRV_PHY_READ);
if (CSR_READ_4(sc, ACXREG_PHY_CTRL) == 0)
CSR_WRITE_4(sc, ACXREG_PHY_CTRL, ACXRV_PHY_WRITE);