e1000: Do not perform reset in reset_task if we are already down

BugLink: https://bugs.launchpad.net/bugs/1900624
[ Upstream commit 49ee3c2ab5234757bfb56a0b3a3cb422f427e3a3 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Ian May <ian.may@canonical.com>

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index f93ed70709c65f753fbd2ab0d9d5fada9ed7b68a..a2ee28e487a6fd20658a5e753f0d60bee78944f1 100644 (file)
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -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);
-       e1000_down(adapter);
-       e1000_up(adapter);
+
+       /* 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);