net: phylink: ensure consistent phy interface mode

[ Upstream commit c6787263 ]

Ensure that we supply the same phy interface mode to mac_link_down() as
we did for the corresponding mac_link_up() call.  This ensures that MAC
drivers that use the phy interface mode in these methods can depend on
mac_link_down() always corresponding to a mac_link_up() call for the
same interface mode.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/phy/phylink.c

@@ -51,6 +51,10 @@ struct phylink {
 
 	/* The link configuration settings */
 	struct phylink_link_state link_config;
+
+	/* The current settings */
+	phy_interface_t cur_interface;
+
 	struct gpio_desc *link_gpio;
 	struct timer_list link_poll;
 	void (*get_fixed_state)(struct net_device *dev,
@@ -453,12 +457,12 @@ static void phylink_resolve(struct work_struct *w)
 		if (!link_state.link) {
 			netif_carrier_off(ndev);
 			pl->ops->mac_link_down(ndev, pl->link_an_mode,
-					       pl->phy_state.interface);
+					       pl->cur_interface);
 			netdev_info(ndev, "Link is Down\n");
 		} else {
+			pl->cur_interface = link_state.interface;
 			pl->ops->mac_link_up(ndev, pl->link_an_mode,
-					     pl->phy_state.interface,
-					     pl->phydev);
+					     pl->cur_interface, pl->phydev);
 
 			netif_carrier_on(ndev);