--- zzzz-none-000/linux-4.9.231/drivers/net/phy/phy_device.c	2020-07-22 07:10:54.000000000 +0000
+++ falcon-5590-729/linux-4.9.231/drivers/net/phy/phy_device.c	2022-03-30 12:03:34.000000000 +0000
@@ -533,6 +533,11 @@
 	if ((phy_id & 0x1fffffff) == 0x1fffffff)
 		return ERR_PTR(-ENODEV);
 
+#if IS_ENABLED(CONFIG_PHY_ID0_JZ_66791_PANIC)
+	if (!phy_id)
+		panic("JZ-66791: mdio bus lockup");
+#endif
+
 	return phy_device_create(bus, addr, phy_id, is_c45, &c45_ids);
 }
 EXPORT_SYMBOL(get_phy_device);
@@ -1009,6 +1014,9 @@
 	struct mii_bus *bus;
 	int i;
 
+	if (phydev->drv && phydev->drv->detach)
+		phydev->drv->detach(phydev);
+
 	phydev->attached_dev->phydev = NULL;
 	phydev->attached_dev = NULL;
 	phy_suspend(phydev);