This is a note to let you know that I've just added the patch titled net/mlx5: Avoid calling sleeping function by the health poll thread to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-mlx5-avoid-calling-sleeping-function-by-the-health-poll-thread.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c1d4d2e92ad670168a17a57dfa182a5a5baa72d4 Mon Sep 17 00:00:00 2001 From: Mohamad Haj Yahia <mohamad@xxxxxxxxxxxx> Date: Thu, 30 Jun 2016 17:34:39 +0300 Subject: net/mlx5: Avoid calling sleeping function by the health poll thread From: Mohamad Haj Yahia <mohamad@xxxxxxxxxxxx> commit c1d4d2e92ad670168a17a57dfa182a5a5baa72d4 upstream. In internal error state the health poll thread will eventually call synchronize_irq() (to safely trigger command completions) which might sleep, so we are calling sleeping function from atomic context which is invalid. Here we move trigger_cmd_completions(dev) to enter error state which is the earliest stage in error state handling. This way we won't need to wait for next health poll to trigger command completions and will solve the scheduling while atomic issue. mlx5_enter_error_state can be called from two contexts, protect it with dev->intf_state_lock Fixes: 89d44f0a6c73 ('net/mlx5_core: Add pci error handlers to mlx5_core driver') Signed-off-by: Mohamad Haj Yahia <mohamad@xxxxxxxxxxxx> Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlx5/core/health.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/health.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/health.c @@ -108,15 +108,21 @@ static int in_fatal(struct mlx5_core_dev void mlx5_enter_error_state(struct mlx5_core_dev *dev) { + mutex_lock(&dev->intf_state_mutex); if (dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR) - return; + goto unlock; mlx5_core_err(dev, "start\n"); - if (pci_channel_offline(dev->pdev) || in_fatal(dev)) + if (pci_channel_offline(dev->pdev) || in_fatal(dev)) { dev->state = MLX5_DEVICE_STATE_INTERNAL_ERROR; + trigger_cmd_completions(dev); + } mlx5_core_event(dev, MLX5_DEV_EVENT_SYS_ERROR, 0); mlx5_core_err(dev, "end\n"); + +unlock: + mutex_unlock(&dev->intf_state_mutex); } static void mlx5_handle_bad_state(struct mlx5_core_dev *dev) @@ -245,7 +251,6 @@ static void poll_health(unsigned long da u32 count; if (dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR) { - trigger_cmd_completions(dev); mod_timer(&health->timer, get_next_poll_jiffies()); return; } Patches currently in stable-queue which might be from mohamad@xxxxxxxxxxxx are queue-4.4/net-mlx5-fix-potential-deadlock-in-command-mode-change.patch queue-4.4/net-mlx5-add-timeout-handle-to-commands-with-callback.patch queue-4.4/net-mlx5-fix-pci-error-recovery-flow.patch queue-4.4/net-mlx5-avoid-calling-sleeping-function-by-the-health-poll-thread.patch