e1000: driver state fixes (race fix)

We were plagued by our interrupt handler posting a watchdog event which
could occur when our adapter was going down in case a late packet arrived
just before e1000_down() finished. This caused the watchdog timer to start
after the NIC was down and keep rescheduling it every N seconds. Once
the driver unloaded it would panic.

Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>

diff --git a/drivers/net/e1000/e1000.h b/drivers/net/e1000/e1000.h
index a9501e7..7ecce43 100644 (file)
--- a/drivers/net/e1000/e1000.h
+++ b/drivers/net/e1000/e1000.h
@@ -345,8 +345,9 @@ struct e1000_adapter {
 };
 
 enum e1000_state_t {
-       __E1000_DRIVER_TESTING,
+       __E1000_TESTING,
        __E1000_RESETTING,
+       __E1000_DOWN
 };
 
 #endif /* _E1000_H_ */

diff --git a/drivers/net/e1000/e1000_ethtool.c b/drivers/net/e1000/e1000_ethtool.c
index 5edf8a0..2cc949a 100644 (file)
--- a/drivers/net/e1000/e1000_ethtool.c
+++ b/drivers/net/e1000/e1000_ethtool.c
@@ -1624,7 +1624,7 @@ e1000_diag_test(struct net_device *netdev,
        struct e1000_adapter *adapter = netdev_priv(netdev);
        boolean_t if_running = netif_running(netdev);
 
-       set_bit(__E1000_DRIVER_TESTING, &adapter->flags);
+       set_bit(__E1000_TESTING, &adapter->flags);
        if (eth_test->flags == ETH_TEST_FL_OFFLINE) {
                /* Offline tests */
 
@@ -1669,7 +1669,7 @@ e1000_diag_test(struct net_device *netdev,
                adapter->hw.autoneg = autoneg;
 
                e1000_reset(adapter);
-               clear_bit(__E1000_DRIVER_TESTING, &adapter->flags);
+               clear_bit(__E1000_TESTING, &adapter->flags);
                if (if_running)
                        dev_open(netdev);
        } else {
@@ -1684,7 +1684,7 @@ e1000_diag_test(struct net_device *netdev,
                data[2] = 0;
                data[3] = 0;
 
-               clear_bit(__E1000_DRIVER_TESTING, &adapter->flags);
+               clear_bit(__E1000_TESTING, &adapter->flags);
        }
        msleep_interruptible(4 * 1000);
 }

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index e261578..5098dd7 100644 (file)
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -476,13 +476,14 @@ e1000_up(struct e1000_adapter *adapter)
 
        adapter->tx_queue_len = netdev->tx_queue_len;
 
-       mod_timer(&adapter->watchdog_timer, jiffies);
-
 #ifdef CONFIG_E1000_NAPI
        netif_poll_enable(netdev);
 #endif
        e1000_irq_enable(adapter);
 
+       clear_bit(__E1000_DOWN, &adapter->flags);
+
+       mod_timer(&adapter->watchdog_timer, jiffies + 2 * HZ);
        return 0;
 }
 
@@ -561,6 +562,10 @@ e1000_down(struct e1000_adapter *adapter)
 {
        struct net_device *netdev = adapter->netdev;
 
+       /* signal that we're down so the interrupt handler does not
+        * reschedule our watchdog timer */
+       set_bit(__E1000_DOWN, &adapter->flags);
+
        e1000_irq_disable(adapter);
 
        del_timer_sync(&adapter->tx_fifo_stall_timer);
@@ -903,11 +908,6 @@ e1000_probe(struct pci_dev *pdev,
        INIT_WORK(&adapter->reset_task,
                (void (*)(void *))e1000_reset_task, netdev);
 
-       /* we're going to reset, so assume we have no link for now */
-
-       netif_carrier_off(netdev);
-       netif_stop_queue(netdev);
-
        e1000_check_options(adapter);
 
        /* Initial Wake on LAN setting
@@ -1014,6 +1014,10 @@ e1000_probe(struct pci_dev *pdev,
        if ((err = register_netdev(netdev)))
                goto err_register;
 
+       /* tell the stack to leave us alone until e1000_open() is called */
+       netif_carrier_off(netdev);
+       netif_stop_queue(netdev);
+
        DPRINTK(PROBE, INFO, "Intel(R) PRO/1000 Network Connection\n");
 
        cards_found++;
@@ -1200,6 +1204,8 @@ e1000_sw_init(struct e1000_adapter *adapter)
        atomic_set(&adapter->irq_sem, 1);
        spin_lock_init(&adapter->stats_lock);
 
+       set_bit(__E1000_DOWN, &adapter->flags);
+
        return 0;
 }
 
@@ -1265,7 +1271,7 @@ e1000_open(struct net_device *netdev)
        int err;
 
        /* disallow open during test */
-       if (test_bit(__E1000_DRIVER_TESTING, &adapter->flags))
+       if (test_bit(__E1000_TESTING, &adapter->flags))
                return -EBUSY;
 
        /* allocate transmit descriptors */
@@ -3072,7 +3078,7 @@ e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
        if (unlikely(adapter->hw.mac_type == e1000_82547)) {
                if (unlikely(e1000_82547_fifo_workaround(adapter, skb))) {
                        netif_stop_queue(netdev);
-                       mod_timer(&adapter->tx_fifo_stall_timer, jiffies);
+                       mod_timer(&adapter->tx_fifo_stall_timer, jiffies + 1);
                        spin_unlock_irqrestore(&tx_ring->tx_lock, flags);
                        return NETDEV_TX_BUSY;
                }
@@ -3468,7 +3474,9 @@ e1000_intr(int irq, void *data, struct pt_regs *regs)
                        rctl = E1000_READ_REG(hw, RCTL);
                        E1000_WRITE_REG(hw, RCTL, rctl & ~E1000_RCTL_EN);
                }
-               mod_timer(&adapter->watchdog_timer, jiffies);
+               /* guard against interrupt when we're going down */
+               if (!test_bit(__E1000_DOWN, &adapter->flags))
+                       mod_timer(&adapter->watchdog_timer, jiffies + 1);
        }
 
 #ifdef CONFIG_E1000_NAPI