net: PHYLIB mdio fixes #2

The PHYLIB mdio code has more problems in error paths:
- mdiobus_release can be called before bus->state is set to
  MDIOBUS_REGISTERED
- mdiobus_scan allocates resources which need to be freed
- the comment is wrong, the resistors used are actually pull-ups.

Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 8 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 7a333601fbe8..11adf6ed4628 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -63,7 +63,9 @@ EXPORT_SYMBOL(mdiobus_alloc);
 static void mdiobus_release(struct device *d)
 {
         struct mii_bus *bus = to_mii_bus(d);
-        BUG_ON(bus->state != MDIOBUS_RELEASED);
+        BUG_ON(bus->state != MDIOBUS_RELEASED &&
+               /* for compatibility with error handling in drivers */
+               bus->state != MDIOBUS_ALLOCATED);
         kfree(bus);
 }
 
@@ -83,8 +85,7 @@ static struct class mdio_bus_class = {
  */
 int mdiobus_register(struct mii_bus *bus)
 {
-        int i;
-        int err = 0;
+        int i, err;
 
         if (NULL == bus || NULL == bus->name ||
                         NULL == bus->read ||
@@ -116,16 +117,23 @@ int mdiobus_register(struct mii_bus *bus)
                         struct phy_device *phydev;
 
                         phydev = mdiobus_scan(bus, i);
-                        if (IS_ERR(phydev))
+                        if (IS_ERR(phydev)) {
                                 err = PTR_ERR(phydev);
+                                goto error;
+                        }
                 }
         }
 
-        if (!err)
-                bus->state = MDIOBUS_REGISTERED;
-
+        bus->state = MDIOBUS_REGISTERED;
         pr_info("%s: probed\n", bus->name);
+        return 0;
 
+error:
+        while (--i >= 0) {
+                if (bus->phy_map[i])
+                        device_unregister(&bus->phy_map[i]->dev);
+        }
+        device_del(&bus->dev);
         return err;
 }
 EXPORT_SYMBOL(mdiobus_register);
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index f84f6a1b530c..e35460165bf7 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -232,7 +232,7 @@ struct phy_device * get_phy_device(struct mii_bus *bus, int addr)
                 return NULL;
 
         /*
-         * Broken hardware is sometimes missing the pull down resistor on the
+         * Broken hardware is sometimes missing the pull-up resistor on the
          * MDIO line, which results in reads to non-existent devices returning
          * 0 rather than 0xffff. Catch this here and treat 0 as a non-existent
          * device as well.