PSF_CFG0
ext_write(0, phydev, PAGE5, PSF_CFG0, cfg0);
tmp->cfg0 = ext_read(tmp->phydev, PAGE5, PSF_CFG0);
ext_write(0, tmp->phydev, PAGE5, PSF_CFG0, 0);
cfg0 = ext_read(master, PAGE5, PSF_CFG0);
ext_write(0, master, PAGE5, PSF_CFG0, 0);
ext_write(0, tmp->phydev, PAGE5, PSF_CFG0, tmp->cfg0);
ext_write(0, master, PAGE5, PSF_CFG0, cfg0);