net: phy: make phy_suspend a no-op if PHY is suspended already

Gently handle the case that phy_suspend() is called whilst PHY is in
power-down.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -1524,6 +1524,9 @@ int phy_suspend(struct phy_device *phydev)
 	struct phy_driver *phydrv = phydev->drv;
 	int ret;
 
+	if (phydev->suspended)
+		return 0;
+
 	/* If the device has WOL enabled, we cannot suspend the PHY */
 	phy_ethtool_get_wol(phydev, &wol);
 	if (wol.wolopts || (netdev && netdev->wol_enabled))