net: phylink: add phylink_link_is_up() helper

Add a helper to determine whether the link is up or down. Currently
this is only used in one location, but becomes necessary to test
when reconfiguring EEE.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/E1tYADl-0014Ph-EV@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Russell King (Oracle)

drivers/net/phy/phylink.c

@@ -1651,20 +1651,21 @@ static void phylink_link_down(struct phylink *pl)
 	phylink_info(pl, "Link is Down\n");
 }
 
+static bool phylink_link_is_up(struct phylink *pl)
+{
+	return pl->netdev ? netif_carrier_ok(pl->netdev) : pl->old_link_state;
+}
+
 static void phylink_resolve(struct work_struct *w)
 {
 	struct phylink *pl = container_of(w, struct phylink, resolve);
 	struct phylink_link_state link_state;
-	struct net_device *ndev = pl->netdev;
 	bool mac_config = false;
 	bool retrigger = false;
 	bool cur_link_state;
 
 	mutex_lock(&pl->state_mutex);
-	if (pl->netdev)
-		cur_link_state = netif_carrier_ok(ndev);
-	else
-		cur_link_state = pl->old_link_state;
+	cur_link_state = phylink_link_is_up(pl);
 
 	if (pl->phylink_disable_state) {
 		pl->link_failed = false;