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    Subject[PATCH AUTOSEL 5.4 280/330] e1000: Do not perform reset in reset_task if we are already down
    Date
    From: Alexander Duyck <alexander.h.duyck@linux.intel.com>

    [ 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>
    ---
    drivers/net/ethernet/intel/e1000/e1000_main.c | 18 ++++++++++++++----
    1 file changed, 14 insertions(+), 4 deletions(-)

    diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
    index f93ed70709c65..a2ee28e487a6f 100644
    --- 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);
    --
    2.25.1
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