*/
 static int genphy_c45_baset1_an_config_aneg(struct phy_device *phydev)
 {
+       u16 adv_l_mask, adv_l = 0;
+       u16 adv_m_mask, adv_m = 0;
        int changed = 0;
-       u16 adv_l = 0;
-       u16 adv_m = 0;
        int ret;
 
+       adv_l_mask = MDIO_AN_T1_ADV_L_FORCE_MS | MDIO_AN_T1_ADV_L_PAUSE_CAP |
+               MDIO_AN_T1_ADV_L_PAUSE_ASYM;
+       adv_m_mask = MDIO_AN_T1_ADV_M_MST | MDIO_AN_T1_ADV_M_B10L;
+
        switch (phydev->master_slave_set) {
        case MASTER_SLAVE_CFG_MASTER_FORCE:
+               adv_m |= MDIO_AN_T1_ADV_M_MST;
+               fallthrough;
        case MASTER_SLAVE_CFG_SLAVE_FORCE:
                adv_l |= MDIO_AN_T1_ADV_L_FORCE_MS;
                break;
        case MASTER_SLAVE_CFG_MASTER_PREFERRED:
+               adv_m |= MDIO_AN_T1_ADV_M_MST;
+               fallthrough;
        case MASTER_SLAVE_CFG_SLAVE_PREFERRED:
                break;
        case MASTER_SLAVE_CFG_UNKNOWN:
        case MASTER_SLAVE_CFG_UNSUPPORTED:
-               return 0;
+               /* if master/slave role is not specified, do not overwrite it */
+               adv_l_mask &= ~MDIO_AN_T1_ADV_L_FORCE_MS;
+               adv_m_mask &= ~MDIO_AN_T1_ADV_M_MST;
+               break;
        default:
                phydev_warn(phydev, "Unsupported Master/Slave mode\n");
                return -EOPNOTSUPP;
        }
 
-       switch (phydev->master_slave_set) {
-       case MASTER_SLAVE_CFG_MASTER_FORCE:
-       case MASTER_SLAVE_CFG_MASTER_PREFERRED:
-               adv_m |= MDIO_AN_T1_ADV_M_MST;
-               break;
-       case MASTER_SLAVE_CFG_SLAVE_FORCE:
-       case MASTER_SLAVE_CFG_SLAVE_PREFERRED:
-               break;
-       default:
-               break;
-       }
-
        adv_l |= linkmode_adv_to_mii_t1_adv_l_t(phydev->advertising);
 
        ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, MDIO_AN_T1_ADV_L,
-                                    (MDIO_AN_T1_ADV_L_FORCE_MS | MDIO_AN_T1_ADV_L_PAUSE_CAP
-                                    | MDIO_AN_T1_ADV_L_PAUSE_ASYM), adv_l);
+                                    adv_l_mask, adv_l);
        if (ret < 0)
                return ret;
        if (ret > 0)
        adv_m |= linkmode_adv_to_mii_t1_adv_m_t(phydev->advertising);
 
        ret = phy_modify_mmd_changed(phydev, MDIO_MMD_AN, MDIO_AN_T1_ADV_M,
-                                    MDIO_AN_T1_ADV_M_MST | MDIO_AN_T1_ADV_M_B10L, adv_m);
+                                    adv_m_mask, adv_m);
        if (ret < 0)
                return ret;
        if (ret > 0)