net/mlx5: Use del_timer_sync in fw reset flow of halting poll

msanalla · Saeed Mahameed · commit 3c5193a87b0f · 2022-02-01T20:59:40.000-08:00
Substitute del_timer() with del_timer_sync() in fw reset polling deactivation flow, in order to prevent a race condition which occurs when del_timer() is called and timer is deactivated while another process is handling the timer interrupt. A situation that led to the following call trace: RIP: 0010:run_timer_softirq+0x137/0x420 <IRQ> recalibrate_cpu_khz+0x10/0x10 ktime_get+0x3e/0xa0 ? sched_clock_cpu+0xb/0xc0 __do_softirq+0xf5/0x2ea irq_exit_rcu+0xc1/0xf0 sysvec_apic_timer_interrupt+0x9e/0xc0 asm_sysvec_apic_timer_interrupt+0x12/0x20 </IRQ> Fixes: 38b9f90 ("net/mlx5: Handle sync reset request event") Signed-off-by: Maher Sanalla <msanalla@nvidia.com> Reviewed-by: Moshe Shemesh <moshe@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
@@ -132,7 +132,7 @@ static void mlx5_stop_sync_reset_poll(struct mlx5_core_dev *dev)
 {
 	struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset;
 
-	del_timer(&fw_reset->timer);
+	del_timer_sync(&fw_reset->timer);
 }
 
 static void mlx5_sync_reset_clear_reset_requested(struct mlx5_core_dev *dev, bool poll_health)

Original file line number	Diff line number	Diff line change
`@@ -132,7 +132,7 @@ static void mlx5_stop_sync_reset_poll(struct mlx5_core_dev *dev)`
`132`	`132`	`{`
`133`	`133`	`struct mlx5_fw_reset *fw_reset = dev->priv.fw_reset;`
`134`	`134`
`135`		`- del_timer(&fw_reset->timer);`
	`135`	`+ del_timer_sync(&fw_reset->timer);`
`136`	`136`	`}`
`137`	`137`
`138`	`138`	`static void mlx5_sync_reset_clear_reset_requested(struct mlx5_core_dev *dev, bool poll_health)`