The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From cb7786a76ea39f394f0a059787fe24fa8e340fb6 Mon Sep 17 00:00:00 2001 From: Moshe Shemesh moshe@nvidia.com Date: Mon, 11 Apr 2022 21:31:06 +0300 Subject: [PATCH] net/mlx5: Fix deadlock in sync reset flow
The sync reset flow can lead to the following deadlock when poll_sync_reset() is called by timer softirq and waiting on del_timer_sync() for the same timer. Fix that by moving the part of the flow that waits for the timer to reset_reload_work.
It fixes the following kernel Trace: RIP: 0010:del_timer_sync+0x32/0x40 ... Call Trace: <IRQ> mlx5_sync_reset_clear_reset_requested+0x26/0x50 [mlx5_core] poll_sync_reset.cold+0x36/0x52 [mlx5_core] call_timer_fn+0x32/0x130 __run_timers.part.0+0x180/0x280 ? tick_sched_handle+0x33/0x60 ? tick_sched_timer+0x3d/0x80 ? ktime_get+0x3e/0xa0 run_timer_softirq+0x2a/0x50 __do_softirq+0xe1/0x2d6 ? hrtimer_interrupt+0x136/0x220 irq_exit+0xae/0xb0 smp_apic_timer_interrupt+0x7b/0x140 apic_timer_interrupt+0xf/0x20 </IRQ>
Fixes: 3c5193a87b0f ("net/mlx5: Use del_timer_sync in fw reset flow of halting poll") Signed-off-by: Moshe Shemesh moshe@nvidia.com Reviewed-by: Maher Sanalla msanalla@nvidia.com Signed-off-by: Saeed Mahameed saeedm@nvidia.com
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c index 4aa22dce9b77..ec18d4ccbc11 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/fw_reset.c @@ -155,22 +155,6 @@ static void mlx5_fw_reset_complete_reload(struct mlx5_core_dev *dev) } }
-static void mlx5_sync_reset_reload_work(struct work_struct *work) -{ - struct mlx5_fw_reset *fw_reset = container_of(work, struct mlx5_fw_reset, - reset_reload_work); - struct mlx5_core_dev *dev = fw_reset->dev; - int err; - - mlx5_enter_error_state(dev, true); - mlx5_unload_one(dev); - err = mlx5_health_wait_pci_up(dev); - if (err) - mlx5_core_err(dev, "reset reload flow aborted, PCI reads still not working\n"); - fw_reset->ret = err; - mlx5_fw_reset_complete_reload(dev); -} - static void mlx5_stop_sync_reset_poll(struct mlx5_core_dev *dev) { struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset; @@ -188,6 +172,23 @@ static void mlx5_sync_reset_clear_reset_requested(struct mlx5_core_dev *dev, boo mlx5_start_health_poll(dev); }
+static void mlx5_sync_reset_reload_work(struct work_struct *work) +{ + struct mlx5_fw_reset *fw_reset = container_of(work, struct mlx5_fw_reset, + reset_reload_work); + struct mlx5_core_dev *dev = fw_reset->dev; + int err; + + mlx5_sync_reset_clear_reset_requested(dev, false); + mlx5_enter_error_state(dev, true); + mlx5_unload_one(dev); + err = mlx5_health_wait_pci_up(dev); + if (err) + mlx5_core_err(dev, "reset reload flow aborted, PCI reads still not working\n"); + fw_reset->ret = err; + mlx5_fw_reset_complete_reload(dev); +} + #define MLX5_RESET_POLL_INTERVAL (HZ / 10) static void poll_sync_reset(struct timer_list *t) { @@ -202,7 +203,6 @@ static void poll_sync_reset(struct timer_list *t)
if (fatal_error) { mlx5_core_warn(dev, "Got Device Reset\n"); - mlx5_sync_reset_clear_reset_requested(dev, false); queue_work(fw_reset->wq, &fw_reset->reset_reload_work); return; }