+static inline void mii_eee_100_10000_adv_mod_linkmode_t(unsigned long *adv,
+							u32 val)
+{
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
+			 adv, val & MDIO_EEE_100TX);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
+			 adv, val & MDIO_EEE_1000T);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_10000baseT_Full_BIT,
+			 adv, val & MDIO_EEE_10GT);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_1000baseKX_Full_BIT,
+			 adv, val & MDIO_EEE_1000KX);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT,
+			 adv, val & MDIO_EEE_10GKX4);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_10000baseKR_Full_BIT,
+			 adv, val & MDIO_EEE_10GKR);
+}

This and mmd_eee_cap_to_ethtool_sup_t() are very similar. Could you
try to remove the duplication. Maybe
ethtool_convert_link_mode_to_legacy_u32() could be used?

	Andrew