From: Ido Schimmel idosch@nvidia.com
[ Upstream commit 1f492eab67bced119a0ac7db75ef2047e29a30c6 ]
The driver sends Ethernet Management Datagram (EMAD) packets to the device for configuration purposes and waits for up to 200ms for a reply. A request is retried up to 5 times.
When the system is under heavy load, replies are not always processed in time and EMAD transactions fail.
Make the process more robust to such delays by using exponential backoff. First wait for up to 200ms, then retransmit and wait for up to 400ms and so on.
Fixes: caf7297e7ab5 ("mlxsw: core: Introduce support for asynchronous EMAD register access") Reported-by: Denis Yulevich denisyu@nvidia.com Tested-by: Denis Yulevich denisyu@nvidia.com Signed-off-by: Ido Schimmel idosch@nvidia.com Reviewed-by: Jiri Pirko jiri@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/mellanox/mlxsw/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c +++ b/drivers/net/ethernet/mellanox/mlxsw/core.c @@ -436,7 +436,7 @@ static void mlxsw_emad_trans_timeout_sch { unsigned long timeout = msecs_to_jiffies(MLXSW_EMAD_TIMEOUT_MS);
- mlxsw_core_schedule_dw(&trans->timeout_dw, timeout); + mlxsw_core_schedule_dw(&trans->timeout_dw, timeout << trans->retries); }
static int mlxsw_emad_transmit(struct mlxsw_core *mlxsw_core,