From 53013c77437c9b00658fc112b4e0aecd221c512a Mon Sep 17 00:00:00 2001
From: Florian Fainelli <f.fainelli@gmail.com>
Date: Thu, 11 Dec 2014 12:49:15 -0800
Subject: net: dsa: handle non-existing PHYs on switch internal bus

In case there is no PHY at the designated address on the internal
switch, we would basically de-reference a null pointer here:

dsa_slave_phy_setup(...)
{
	p->phy = ds->slave_mii_bus->phy_map[p->port];
	phy_connect_direct(slave_dev, p->phy, dsa_slave_adjust_link,
				      ^------

This can be triggered when the platform configuration (platform_data or
Device Tree) indicates there should be a PHY device at this address, but
the HW is non-responsive, such that we cannot attach a PHY device at
this specific location.

Fix this by checking the return value prior to calling
phy_connect_direct().

CC: Andrew Lunn <andrew@lunn.ch>
Fixes: b31f65fb4383 ("net: dsa: slave: Fix autoneg for phys on switch MDIO bus")
Reported-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrey Volkov <andrey.volkov@nexvision.fr>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 528380a..da64ba9 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -555,6 +555,9 @@ static void dsa_slave_phy_setup(struct dsa_slave_priv *p,
 	 */
 	if (!p->phy) {
 		p->phy = ds->slave_mii_bus->phy_map[p->port];
+		if (!p->phy)
+			return;
+
 		phy_connect_direct(slave_dev, p->phy, dsa_slave_adjust_link,
 				   p->phy_interface);
 	} else {
-- 
cgit v0.10.2


From 9697f1cde9901c00298fd1313b4aaf96f287bf7a Mon Sep 17 00:00:00 2001
From: Florian Fainelli <f.fainelli@gmail.com>
Date: Thu, 11 Dec 2014 12:49:16 -0800
Subject: net: dsa: propagate error code from dsa_slave_phy_setup

In case we cannot attach to our slave netdevice PHY, error out and
propagate that error up to the caller: dsa_slave_create().

Fixes: 0d8bcdd383b8 ("net: dsa: allow for more complex PHY setups")
Signed-off-by: Andrey Volkov <andrey.volkov@nexvision.fr>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index da64ba9..515569f 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -512,7 +512,7 @@ static int dsa_slave_fixed_link_update(struct net_device *dev,
 }
 
 /* slave device setup *******************************************************/
-static void dsa_slave_phy_setup(struct dsa_slave_priv *p,
+static int dsa_slave_phy_setup(struct dsa_slave_priv *p,
 				struct net_device *slave_dev)
 {
 	struct dsa_switch *ds = p->parent;
@@ -533,7 +533,7 @@ static void dsa_slave_phy_setup(struct dsa_slave_priv *p,
 		ret = of_phy_register_fixed_link(port_dn);
 		if (ret) {
 			netdev_err(slave_dev, "failed to register fixed PHY\n");
-			return;
+			return ret;
 		}
 		phy_is_fixed = true;
 		phy_dn = port_dn;
@@ -556,7 +556,7 @@ static void dsa_slave_phy_setup(struct dsa_slave_priv *p,
 	if (!p->phy) {
 		p->phy = ds->slave_mii_bus->phy_map[p->port];
 		if (!p->phy)
-			return;
+			return -ENODEV;
 
 		phy_connect_direct(slave_dev, p->phy, dsa_slave_adjust_link,
 				   p->phy_interface);
@@ -564,6 +564,8 @@ static void dsa_slave_phy_setup(struct dsa_slave_priv *p,
 		netdev_info(slave_dev, "attached PHY at address %d [%s]\n",
 			    p->phy->addr, p->phy->drv->name);
 	}
+
+	return 0;
 }
 
 int dsa_slave_suspend(struct net_device *slave_dev)
@@ -656,12 +658,17 @@ dsa_slave_create(struct dsa_switch *ds, struct device *parent,
 	p->old_link = -1;
 	p->old_duplex = -1;
 
-	dsa_slave_phy_setup(p, slave_dev);
+	ret = dsa_slave_phy_setup(p, slave_dev);
+	if (ret) {
+		free_netdev(slave_dev);
+		return NULL;
+	}
 
 	ret = register_netdev(slave_dev);
 	if (ret) {
 		netdev_err(master, "error %d registering interface %s\n",
 			   ret, slave_dev->name);
+		phy_disconnect(p->phy);
 		free_netdev(slave_dev);
 		return NULL;
 	}
-- 
cgit v0.10.2