Merge branch 'stmmac-wol-fix'

Joakim Zhang says:

====================
net: stmmac: fix WoL issue

This patch set fixes stmmac not working after system resume back with WoL
active. Thanks a lot for Russell King keeps looking into this issue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 103 insertions, 18 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 97238359e101..ece02b35a6ce 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7123,8 +7123,6 @@ int stmmac_suspend(struct device *dev)
 	if (!ndev || !netif_running(ndev))
 		return 0;
 
-	phylink_mac_change(priv->phylink, false);
-
 	mutex_lock(&priv->lock);
 
 	netif_device_detach(ndev);
@@ -7150,14 +7148,6 @@ int stmmac_suspend(struct device *dev)
 		stmmac_pmt(priv, priv->hw, priv->wolopts);
 		priv->irq_wake = 1;
 	} else {
-		mutex_unlock(&priv->lock);
-		rtnl_lock();
-		if (device_may_wakeup(priv->device))
-			phylink_speed_down(priv->phylink, false);
-		phylink_stop(priv->phylink);
-		rtnl_unlock();
-		mutex_lock(&priv->lock);
-
 		stmmac_mac_set(priv, priv->ioaddr, false);
 		pinctrl_pm_select_sleep_state(priv->device);
 		/* Disable clock in case of PWM is off */
@@ -7171,6 +7161,16 @@ int stmmac_suspend(struct device *dev)
 
 	mutex_unlock(&priv->lock);
 
+	rtnl_lock();
+	if (device_may_wakeup(priv->device) && priv->plat->pmt) {
+		phylink_suspend(priv->phylink, true);
+	} else {
+		if (device_may_wakeup(priv->device))
+			phylink_speed_down(priv->phylink, false);
+		phylink_suspend(priv->phylink, false);
+	}
+	rtnl_unlock();
+
 	if (priv->dma_cap.fpesel) {
 		/* Disable FPE */
 		stmmac_fpe_configure(priv, priv->ioaddr,
@@ -7261,13 +7261,15 @@ int stmmac_resume(struct device *dev)
 			return ret;
 	}
 
-	if (!device_may_wakeup(priv->device) || !priv->plat->pmt) {
-		rtnl_lock();
-		phylink_start(priv->phylink);
-		/* We may have called phylink_speed_down before */
-		phylink_speed_up(priv->phylink);
-		rtnl_unlock();
+	rtnl_lock();
+	if (device_may_wakeup(priv->device) && priv->plat->pmt) {
+		phylink_resume(priv->phylink);
+	} else {
+		phylink_resume(priv->phylink);
+		if (device_may_wakeup(priv->device))
+			phylink_speed_up(priv->phylink);
 	}
+	rtnl_unlock();
 
 	rtnl_lock();
 	mutex_lock(&priv->lock);
@@ -7288,8 +7290,6 @@ int stmmac_resume(struct device *dev)
 	mutex_unlock(&priv->lock);
 	rtnl_unlock();
 
-	phylink_mac_change(priv->phylink, true);
-
 	netif_device_attach(ndev);
 
 	return 0;
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 2cdf9f989dec..a1464b764d4d 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -33,6 +33,7 @@
 enum {
 	PHYLINK_DISABLE_STOPPED,
 	PHYLINK_DISABLE_LINK,
+	PHYLINK_DISABLE_MAC_WOL,
 };
 
 /**
@@ -1282,6 +1283,9 @@ EXPORT_SYMBOL_GPL(phylink_start);
  * network device driver's &struct net_device_ops ndo_stop() method.  The
  * network device's carrier state should not be changed prior to calling this
  * function.
+ *
+ * This will synchronously bring down the link if the link is not already
+ * down (in other words, it will trigger a mac_link_down() method call.)
  */
 void phylink_stop(struct phylink *pl)
 {
@@ -1302,6 +1306,84 @@ void phylink_stop(struct phylink *pl)
 EXPORT_SYMBOL_GPL(phylink_stop);
 
 /**
+ * phylink_suspend() - handle a network device suspend event
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ * @mac_wol: true if the MAC needs to receive packets for Wake-on-Lan
+ *
+ * Handle a network device suspend event. There are several cases:
+ * - If Wake-on-Lan is not active, we can bring down the link between
+ *   the MAC and PHY by calling phylink_stop().
+ * - If Wake-on-Lan is active, and being handled only by the PHY, we
+ *   can also bring down the link between the MAC and PHY.
+ * - If Wake-on-Lan is active, but being handled by the MAC, the MAC
+ *   still needs to receive packets, so we can not bring the link down.
+ */
+void phylink_suspend(struct phylink *pl, bool mac_wol)
+{
+	ASSERT_RTNL();
+
+	if (mac_wol && (!pl->netdev || pl->netdev->wol_enabled)) {
+		/* Wake-on-Lan enabled, MAC handling */
+		mutex_lock(&pl->state_mutex);
+
+		/* Stop the resolver bringing the link up */
+		__set_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state);
+
+		/* Disable the carrier, to prevent transmit timeouts,
+		 * but one would hope all packets have been sent. This
+		 * also means phylink_resolve() will do nothing.
+		 */
+		netif_carrier_off(pl->netdev);
+
+		/* We do not call mac_link_down() here as we want the
+		 * link to remain up to receive the WoL packets.
+		 */
+		mutex_unlock(&pl->state_mutex);
+	} else {
+		phylink_stop(pl);
+	}
+}
+EXPORT_SYMBOL_GPL(phylink_suspend);
+
+/**
+ * phylink_resume() - handle a network device resume event
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ *
+ * Undo the effects of phylink_suspend(), returning the link to an
+ * operational state.
+ */
+void phylink_resume(struct phylink *pl)
+{
+	ASSERT_RTNL();
+
+	if (test_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state)) {
+		/* Wake-on-Lan enabled, MAC handling */
+
+		/* Call mac_link_down() so we keep the overall state balanced.
+		 * Do this under the state_mutex lock for consistency. This
+		 * will cause a "Link Down" message to be printed during
+		 * resume, which is harmless - the true link state will be
+		 * printed when we run a resolve.
+		 */
+		mutex_lock(&pl->state_mutex);
+		phylink_link_down(pl);
+		mutex_unlock(&pl->state_mutex);
+
+		/* Re-apply the link parameters so that all the settings get
+		 * restored to the MAC.
+		 */
+		phylink_mac_initial_config(pl, true);
+
+		/* Re-enable and re-resolve the link parameters */
+		clear_bit(PHYLINK_DISABLE_MAC_WOL, &pl->phylink_disable_state);
+		phylink_run_resolve(pl);
+	} else {
+		phylink_start(pl);
+	}
+}
+EXPORT_SYMBOL_GPL(phylink_resume);
+
+/**
  * phylink_ethtool_get_wol() - get the wake on lan parameters for the PHY
  * @pl: a pointer to a &struct phylink returned from phylink_create()
  * @wol: a pointer to &struct ethtool_wolinfo to hold the read parameters
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index afb3ded0b691..237291196ce2 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -451,6 +451,9 @@ void phylink_mac_change(struct phylink *, bool up);
 void phylink_start(struct phylink *);
 void phylink_stop(struct phylink *);
 
+void phylink_suspend(struct phylink *pl, bool mac_wol);
+void phylink_resume(struct phylink *pl);
+
 void phylink_ethtool_get_wol(struct phylink *, struct ethtool_wolinfo *);
 int phylink_ethtool_set_wol(struct phylink *, struct ethtool_wolinfo *);