r8169: fix PHY driver check on platforms w/o module softdeps

On Android/x86 the module loading infrastructure can't deal with
softdeps. Therefore the check for presence of the Realtek PHY driver
module fails. mdiobus_register() will try to load the PHY driver
module, therefore move the check to after this call and explicitly
check that a dedicated PHY driver is bound to the PHY device.

Fixes: f32593773549 ("r8169: check that Realtek PHY driver module is loaded")
Reported-by: Chih-Wei Huang <[e-mail]>
Signed-off-by: Heiner Kallweit <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/realtek/r8169_main.c

···
 	if (!tp->phydev) {
 		mdiobus_unregister(new_bus);
 		return -ENODEV;
+	} else if (!tp->phydev->drv) {
+		/* Most chip versions fail with the genphy driver.
+		 * Therefore ensure that the dedicated PHY driver is loaded.
+		 */
+		dev_err(&pdev->dev, "realtek.ko not loaded, maybe it needs to be added to initramfs?\n");
+		mdiobus_unregister(new_bus);
+		return -EUNATCH;
 	}
 
 	/* PHY will be woken up in rtl_open() */
···
 	struct net_device *dev;
 	int chipset, region;
 	int jumbo_max, rc;
-
-	/* Some tools for creating an initramfs don't consider softdeps, then
-	 * r8169.ko may be in initramfs, but realtek.ko not. Then the generic
-	 * PHY driver is used that doesn't work with most chip versions.
-	 */
-	if (!driver_find("RTL8201CP Ethernet", &mdio_bus_type)) {
-		dev_err(&pdev->dev, "realtek.ko not loaded, maybe it needs to be added to initramfs?\n");
-		return -ENOENT;
-	}
 
 	dev = devm_alloc_etherdev(&pdev->dev, sizeof (*tp));
 	if (!dev)