diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index fb633fa3e872f69add5fd0321a173fa9db6f9c1e..6a18a92b5ae3f23fd0c69454c21cb83b0a7c089c 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -917,11 +917,6 @@ int __mdiobus_modify_changed(struct mii_bus *bus, int addr, u32 regnum,
 }
 EXPORT_SYMBOL_GPL(__mdiobus_modify_changed);
 
-static u32 mdiobus_c45_addr(int devad, u16 regnum)
-{
-	return MII_ADDR_C45 | devad << MII_DEVADDR_C45_SHIFT | regnum;
-}
-
 /**
  * __mdiobus_c45_read - Unlocked version of the mdiobus_c45_read function
  * @bus: the mii_bus struct
@@ -942,7 +937,7 @@ int __mdiobus_c45_read(struct mii_bus *bus, int addr, int devad, u32 regnum)
 	if (bus->read_c45)
 		retval = bus->read_c45(bus, addr, devad, regnum);
 	else
-		retval = bus->read(bus, addr, mdiobus_c45_addr(devad, regnum));
+		retval = -EOPNOTSUPP;
 
 	trace_mdio_access(bus, 1, addr, regnum, retval, retval);
 	mdiobus_stats_acct(&bus->stats[addr], true, retval);
@@ -973,8 +968,7 @@ int __mdiobus_c45_write(struct mii_bus *bus, int addr, int devad, u32 regnum,
 	if (bus->write_c45)
 		err = bus->write_c45(bus, addr, devad, regnum, val);
 	else
-		err = bus->write(bus, addr, mdiobus_c45_addr(devad, regnum),
-				 val);
+		err = -EOPNOTSUPP;
 
 	trace_mdio_access(bus, 0, addr, regnum, val, err);
 	mdiobus_stats_acct(&bus->stats[addr], false, err);