* modes mask.
  */
 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
-                                    unsigned long *link_modes)
+                                    const unsigned long *link_modes)
 {
        if (phylink_test(link_modes, 25000baseCR_Full) ||
            phylink_test(link_modes, 25000baseKR_Full) ||
 
 void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
                       unsigned long *support, unsigned long *interfaces);
 phy_interface_t sfp_select_interface(struct sfp_bus *bus,
-                                    unsigned long *link_modes);
+                                    const unsigned long *link_modes);
 
 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo);
 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
 }
 
 static inline phy_interface_t sfp_select_interface(struct sfp_bus *bus,
-                                                  unsigned long *link_modes)
+                                               const unsigned long *link_modes)
 {
        return PHY_INTERFACE_MODE_NA;
 }