From 250ae0d46d857ed61f3e0abf584901e46bd2c638 Mon Sep 17 00:00:00 2001 From: Eli Cohen Date: Sun, 2 Sep 2018 12:01:53 +0300 Subject: [PATCH] net/mlx5: Fix read from coherent memory Use accessor function READ_ONCE to read from coherent memory modified by the device and read by the driver. This becomes most important in preemptive kernels where cond_resched implementation does not have the side effect which guaranteed the updated value. Fixes: 269d26f47f6f ("net/mlx5: Reduce command polling interval") Change-Id: Ie6deeb565ffaf76777b07448c7fbcce3510bbb8a Signed-off-by: Eli Cohen Reported-by: Jesper Dangaard Brouer Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c index 3ce14d42ddc8..a53736c26c0c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c @@ -206,7 +206,7 @@ static void poll_timeout(struct mlx5_cmd_work_ent *ent) u8 own; do { - own = ent->lay->status_own; + own = READ_ONCE(ent->lay->status_own); if (!(own & CMD_OWNER_HW)) { ent->ret = 0; return;