net: of_mdio: fix behavior on missing phy device

of_mdiobus_register creates a phy_device even if get_phy_device failed
to create it previously. This causes indefinite polling on non-existent
PHYs. This fix makes of_mdio_register rely on get_phy_device to
properly create the device or fail otherwise.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/of/of_mdio.c

@@ -84,13 +84,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 		phy = get_phy_device(mdio, addr, is_c45);
 
 		if (!phy || IS_ERR(phy)) {
-			phy = phy_device_create(mdio, addr, 0, false, NULL);
-			if (!phy || IS_ERR(phy)) {
-				dev_err(&mdio->dev,
-					"error creating PHY at address %i\n",
-					addr);
-				continue;
-			}
+			dev_err(&mdio->dev,
+				"cannot get PHY at address %i\n",
+				addr);
+			continue;
 		}
 
 		/* Associate the OF node with the device structure so it