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authorBruce Allan <bruce.w.allan@intel.com>2011-11-29 08:09:19 +0000
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2011-12-05 00:12:22 -0800
commit5f4a780ddd453c4918555fed9d9c5f2d455a087d (patch)
treec538bffc542ce890e94321b6222f2166d1e3e94d /drivers/net/ethernet
parent09357b00255c233705b1cf6d76a8d147340545b8 (diff)
downloadlinux-linaro-stable-5f4a780ddd453c4918555fed9d9c5f2d455a087d.tar.gz
e1000e: hitting BUG_ON() from napi_enable
Based on a patch from Mike McElroy created against the out-of-tree e1000e driver: Hitting the BUG_ON in napi_enable(). Code inspection shows that this can only be triggered by calling napi_enable() twice without an intervening napi_disable(). I saw the following sequence of events in the stack trace: 1) We simulated a cable pull using an Extreme switch. 2) e1000_tx_timeout() was entered. 3) e1000_reset_task() was called. Saw the message from e_err() in the console log. 4) e1000_reinit_locked was called. This function calls e1000_down() and e1000_up(). These functions call napi_disable() and napi_enable() respectively. 5) Then on another thread, a monitor task saw carrier was down and executed 'ip set link down' and 'ip set link up' commands. 6) Saw the '_E1000_RESETTING'warning fron the e1000_close function. 7) Either the e1000_open() executed between the e1000_down() and e1000_up() calls in step 4 or the e1000_open() call executed after the e1000_up() call. In either case, napi_enable() is called twice which triggers the BUG_ON. Signed-off-by: Bruce Allan <bruce.w.allan@intel.com> Cc: Mike McElroy <mike.mcelroy@stratus.com> Tested-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet')
-rw-r--r--drivers/net/ethernet/intel/e1000e/netdev.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index c12df6972b35..93ae0c26d434 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -3516,7 +3516,6 @@ int e1000e_up(struct e1000_adapter *adapter)
clear_bit(__E1000_DOWN, &adapter->state);
- napi_enable(&adapter->napi);
if (adapter->msix_entries)
e1000_configure_msix(adapter);
e1000_irq_enable(adapter);
@@ -3578,7 +3577,6 @@ void e1000e_down(struct e1000_adapter *adapter)
e1e_flush();
usleep_range(10000, 20000);
- napi_disable(&adapter->napi);
e1000_irq_disable(adapter);
del_timer_sync(&adapter->watchdog_timer);
@@ -3901,6 +3899,8 @@ static int e1000_close(struct net_device *netdev)
pm_runtime_get_sync(&pdev->dev);
+ napi_disable(&adapter->napi);
+
if (!test_bit(__E1000_DOWN, &adapter->state)) {
e1000e_down(adapter);
e1000_free_irq(adapter);