6.5-stable review patch. If anyone has any objections, please let me know.
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From: Maher Sanalla msanalla@nvidia.com
[ Upstream commit 92fd39634541eb0a11bf1bafbc8ba92d6ddb8dba ]
Currently, whenever fw issues a change ownership event, the PF that owns the fw tracer drops its ownership directly and the other PFs try to pick up the ownership via what MTRC register suggests.
In some cases, driver releases the ownership of the tracer and reacquires it later on. Whenever the driver releases ownership of the tracer, fw issues a change ownership event. This event can be delayed and come after driver has reacquired ownership of the tracer. Thus the late event will trigger the tracer owner PF to release the ownership again and lead to a scenario where no PF is owning the tracer.
To prevent the scenario described above, when handling a change ownership event, do not drop ownership of the tracer directly, instead read the fw MTRC register to retrieve the up-to-date owner of the tracer and set it accordingly in driver level.
Fixes: f53aaa31cce7 ("net/mlx5: FW tracer, implement tracer logic") Signed-off-by: Maher Sanalla msanalla@nvidia.com Reviewed-by: Shay Drory shayd@nvidia.com Signed-off-by: Saeed Mahameed saeedm@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c b/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c index 7c0f2adbea000..ad789349c06e6 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/diag/fw_tracer.c @@ -848,7 +848,7 @@ static void mlx5_fw_tracer_ownership_change(struct work_struct *work)
mlx5_core_dbg(tracer->dev, "FWTracer: ownership changed, current=(%d)\n", tracer->owner); if (tracer->owner) { - tracer->owner = false; + mlx5_fw_tracer_ownership_acquire(tracer); return; }