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_main.c b/drivers/net/e1000/e1000_main.c
index e261578..5098dd7 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -476,13 +476,14 @@
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 @@
{
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 @@
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 @@
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 @@
atomic_set(&adapter->irq_sem, 1);
spin_lock_init(&adapter->stats_lock);
+ set_bit(__E1000_DOWN, &adapter->flags);
+
return 0;
}
@@ -1265,7 +1271,7 @@
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 @@
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 @@
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