tg3: Fix phylib locking strategy

Felix Radensky noted that chip resets were generating stack trace dumps.
This is because the driver is attempting to acquire the mdio bus mutex
while holding the tp->lock spinlock.  The fix is to change the code such
that every phy access takes the tp->lock spinlock instead.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 27 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index f09bc5dfe8b2..ba5d3fe753b6 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -902,11 +902,12 @@ static int tg3_mdio_read(struct mii_bus *bp, int mii_id, int reg)
         struct tg3 *tp = bp->priv;
         u32 val;
 
-        if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_PAUSED)
-                return -EAGAIN;
+        spin_lock_bh(&tp->lock);
 
         if (tg3_readphy(tp, reg, &val))
-                return -EIO;
+                val = -EIO;
+
+        spin_unlock_bh(&tp->lock);
 
         return val;
 }
@@ -914,14 +915,16 @@ static int tg3_mdio_read(struct mii_bus *bp, int mii_id, int reg)
 static int tg3_mdio_write(struct mii_bus *bp, int mii_id, int reg, u16 val)
 {
         struct tg3 *tp = bp->priv;
+        u32 ret = 0;
 
-        if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_PAUSED)
-                return -EAGAIN;
+        spin_lock_bh(&tp->lock);
 
         if (tg3_writephy(tp, reg, val))
-                return -EIO;
+                ret = -EIO;
 
-        return 0;
+        spin_unlock_bh(&tp->lock);
+
+        return ret;
 }
 
 static int tg3_mdio_reset(struct mii_bus *bp)
@@ -1011,12 +1014,6 @@ static void tg3_mdio_config_5785(struct tg3 *tp)
 
 static void tg3_mdio_start(struct tg3 *tp)
 {
-        if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_INITED) {
-                mutex_lock(&tp->mdio_bus->mdio_lock);
-                tp->tg3_flags3 &= ~TG3_FLG3_MDIOBUS_PAUSED;
-                mutex_unlock(&tp->mdio_bus->mdio_lock);
-        }
-
         tp->mi_mode &= ~MAC_MI_MODE_AUTO_POLL;
         tw32_f(MAC_MI_MODE, tp->mi_mode);
         udelay(80);
@@ -1041,15 +1038,6 @@ static void tg3_mdio_start(struct tg3 *tp)
                 tg3_mdio_config_5785(tp);
 }
 
-static void tg3_mdio_stop(struct tg3 *tp)
-{
-        if (tp->tg3_flags3 & TG3_FLG3_MDIOBUS_INITED) {
-                mutex_lock(&tp->mdio_bus->mdio_lock);
-                tp->tg3_flags3 |= TG3_FLG3_MDIOBUS_PAUSED;
-                mutex_unlock(&tp->mdio_bus->mdio_lock);
-        }
-}
-
 static int tg3_mdio_init(struct tg3 *tp)
 {
         int i;
@@ -1141,7 +1129,6 @@ static void tg3_mdio_fini(struct tg3 *tp)
                 tp->tg3_flags3 &= ~TG3_FLG3_MDIOBUS_INITED;
                 mdiobus_unregister(tp->mdio_bus);
                 mdiobus_free(tp->mdio_bus);
-                tp->tg3_flags3 &= ~TG3_FLG3_MDIOBUS_PAUSED;
         }
 }
 
@@ -1363,7 +1350,7 @@ static void tg3_adjust_link(struct net_device *dev)
         struct tg3 *tp = netdev_priv(dev);
         struct phy_device *phydev = tp->mdio_bus->phy_map[PHY_ADDR];
 
-        spin_lock(&tp->lock);
+        spin_lock_bh(&tp->lock);
 
         mac_mode = tp->mac_mode & ~(MAC_MODE_PORT_MODE_MASK |
                                     MAC_MODE_HALF_DUPLEX);
@@ -1431,7 +1418,7 @@ static void tg3_adjust_link(struct net_device *dev)
         tp->link_config.active_speed = phydev->speed;
         tp->link_config.active_duplex = phydev->duplex;
 
-        spin_unlock(&tp->lock);
+        spin_unlock_bh(&tp->lock);
 
         if (linkmesg)
                 tg3_link_report(tp);
@@ -6392,8 +6379,6 @@ static int tg3_chip_reset(struct tg3 *tp)
 
         tg3_nvram_lock(tp);
 
-        tg3_mdio_stop(tp);
-
         tg3_ape_lock(tp, TG3_APE_LOCK_GRC);
 
         /* No matching tg3_nvram_unlock() after this because
@@ -8698,6 +8683,8 @@ static int tg3_close(struct net_device *dev)
 
         del_timer_sync(&tp->timer);
 
+        tg3_phy_stop(tp);
+
         tg3_full_lock(tp, 1);
 #if 0
         tg3_dump_state(tp);