e1000: Do not perform reset in reset_task if we are already down (49ee3c2a) · Commits · 戴 / test

We are seeing a deadlock in e1000 down when NAPI is being disabled. Looking over the kernel function trace of the system it appears that the interface is being closed and then a reset is hitting which deadlocks the interface as the NAPI interface is already disabled. To prevent this from happening I am disabling the reset task when __E1000_DOWN is already set. In addition code has been added so that we set the __E1000_DOWN while holding the __E1000_RESET flag in e1000_close in order to guarantee that the reset task will not run after we have started the close call. Signed-off-by:

Alexander Duyck <alexander.h.duyck@linux.intel.com> Tested-by:

Maxim Zhukov <mussitantesmortem@gmail.com> Signed-off-by:

Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000/e1000_main.c

+14 −4

Original line number	Diff line number	Diff line
		@@ -542,8 +542,13 @@ void e1000_reinit_locked(struct e1000_adapter *adapter)
		WARN_ON(in_interrupt());
		while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
		msleep(1);

		/* only run the task if not already down */
		if (!test_bit(__E1000_DOWN, &adapter->flags)) {
		e1000_down(adapter);
		e1000_up(adapter);
		}

		clear_bit(__E1000_RESETTING, &adapter->flags);
		}

		@@ -1433,10 +1438,15 @@ int e1000_close(struct net_device *netdev)
		struct e1000_hw *hw = &adapter->hw;
		int count = E1000_CHECK_RESET_COUNT;

		while (test_bit(__E1000_RESETTING, &adapter->flags) && count--)
		while (test_and_set_bit(__E1000_RESETTING, &adapter->flags) && count--)
		usleep_range(10000, 20000);

		WARN_ON(test_bit(__E1000_RESETTING, &adapter->flags));
		WARN_ON(count < 0);

		/* signal that we're down so that the reset task will no longer run */
		set_bit(__E1000_DOWN, &adapter->flags);
		clear_bit(__E1000_RESETTING, &adapter->flags);

		e1000_down(adapter);
		e1000_power_down_phy(adapter);
		e1000_free_irq(adapter);

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