From: Russell King <rmk+kernel@armlinux.org.uk>
Date: Mon, 19 Dec 2016 12:17:57 +0000
Subject: [PATCH] phylink: ensure link drops are reported

When the MAC reports a link failure, it can be momentary.  Ensure
that the event is reported by latching the loss of link, so that the
worker reports link down.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---

--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -60,6 +60,8 @@ struct phylink {
 	struct phylink_link_state phy_state;
 	struct work_struct resolve;
 
+	bool mac_link_dropped;
+
 	const struct phylink_module_ops *module_ops;
 	void *module_data;
 };
@@ -340,6 +342,9 @@ static void phylink_resolve(struct work_
 
 	mutex_lock(&pl->state_mutex);
 	if (pl->phylink_disable_state) {
+		pl->mac_link_dropped = false;
+		link_state.link = false;
+	} else if (pl->mac_link_dropped) {
 		link_state.link = false;
 	} else {
 		switch (pl->link_an_mode) {
@@ -405,6 +410,10 @@ static void phylink_resolve(struct work_
 				    phylink_pause_to_str(link_state.pause));
 		}
 	}
+	if (!link_state.link && pl->mac_link_dropped) {
+		pl->mac_link_dropped = false;
+		queue_work(system_power_efficient_wq, &pl->resolve);
+	}
 	mutex_unlock(&pl->state_mutex);
 }
 
@@ -641,6 +650,8 @@ EXPORT_SYMBOL_GPL(phylink_disconnect_phy
 
 void phylink_mac_change(struct phylink *pl, bool up)
 {
+	if (!up)
+		pl->mac_link_dropped = true;
 	phylink_run_resolve(pl);
 	netdev_dbg(pl->netdev, "mac link %s\n", up ? "up" : "down");
 }