net/mlx5: Fix frequent ioread PCI access during recovery

Moshe Shemesh · Saeed Mahameed · commit 8c702a53bb0a · 2020-04-08T15:46:36.000-07:00
High frequency of PCI ioread calls during recovery flow may cause the following trace on powerpc: [ 248.670288] EEH: 2100000 reads ignored for recovering device at location=Slot1 driver=mlx5_core pci addr=0000:01:00.1 [ 248.670331] EEH: Might be infinite loop in mlx5_core driver [ 248.670361] CPU: 2 PID: 35247 Comm: kworker/u192:11 Kdump: loaded Tainted: G OE ------------ 4.14.0-115.14.1.el7a.ppc64le #1 [ 248.670425] Workqueue: mlx5_health0000:01:00.1 health_recover_work [mlx5_core] [ 248.670471] Call Trace: [ 248.670492] [c00020391c11b960] [c000000000c217ac] dump_stack+0xb0/0xf4 (unreliable) [ 248.670548] [c00020391c11b9a0] [c000000000045818] eeh_check_failure+0x5c8/0x630 [ 248.670631] [c00020391c11ba50] [c00000000068fce4] ioread32be+0x114/0x1c0 [ 248.670692] [c00020391c11bac0] [c00800000dd8b400] mlx5_error_sw_reset+0x160/0x510 [mlx5_core] [ 248.670752] [c00020391c11bb60] [c00800000dd75824] mlx5_disable_device+0x34/0x1d0 [mlx5_core] [ 248.670822] [c00020391c11bbe0] [c00800000dd8affc] health_recover_work+0x11c/0x3c0 [mlx5_core] [ 248.670891] [c00020391c11bc80] [c000000000164fcc] process_one_work+0x1bc/0x5f0 [ 248.670955] [c00020391c11bd20] [c000000000167f8c] worker_thread+0xac/0x6b0 [ 248.671015] [c00020391c11bdc0] [c000000000171618] kthread+0x168/0x1b0 [ 248.671067] [c00020391c11be30] [c00000000000b65c] ret_from_kernel_thread+0x5c/0x80 Reduce the PCI ioread frequency during recovery by using msleep() instead of cond_resched() Fixes: 3e5b72a ("net/mlx5: Issue SW reset on FW assert") Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Reviewed-by: Feras Daoud <ferasda@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/health.c b/drivers/net/ethernet/mellanox/mlx5/core/health.c
@@ -243,7 +243,7 @@ void mlx5_error_sw_reset(struct mlx5_core_dev *dev)
 		if (mlx5_get_nic_state(dev) == MLX5_NIC_IFC_DISABLED)
 			break;
 
-		cond_resched();
+		msleep(20);
 	} while (!time_after(jiffies, end));
 
 	if (mlx5_get_nic_state(dev) != MLX5_NIC_IFC_DISABLED) {
