This is a note to let you know that I've just added the patch titled net/mlx5e: Get the latest values from counters in switchdev mode to the 5.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-mlx5e-get-the-latest-values-from-counters-in-switchdev-mode.patch and it can be found in the queue-5.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From dcdf4ce0ff4ba206fc362e149c8ae81d6a2f849c Mon Sep 17 00:00:00 2001 From: Zhu Yanjun <yanjunz@xxxxxxxxxxxx> Date: Wed, 8 Apr 2020 14:51:52 +0800 Subject: net/mlx5e: Get the latest values from counters in switchdev mode From: Zhu Yanjun <yanjunz@xxxxxxxxxxxx> commit dcdf4ce0ff4ba206fc362e149c8ae81d6a2f849c upstream. In the switchdev mode, when running "cat /sys/class/net/NIC/statistics/tx_packets", the ppcnt register is accessed to get the latest values. But currently this command can not get the correct values from ppcnt. >From firmware manual, before getting the 802_3 counters, the 802_3 data layout should be set to the ppcnt register. When the command "cat /sys/class/net/NIC/statistics/tx_packets" is run, before updating 802_3 data layout with ppcnt register, the monitor counters are tested. The test result will decide the 802_3 data layout is updated or not. Actually the monitor counters do not support to monitor rx/tx stats of 802_3 in switchdev mode. So the rx/tx counters change will not trigger monitor counters. So the 802_3 data layout will not be updated in ppcnt register. Finally this command can not get the latest values from ppcnt register with 802_3 data layout. Fixes: 5c7e8bbb0257 ("net/mlx5e: Use monitor counters for update stats") Signed-off-by: Zhu Yanjun <yanjunz@xxxxxxxxxxxx> Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -3568,7 +3568,12 @@ mlx5e_get_stats(struct net_device *dev, struct mlx5e_vport_stats *vstats = &priv->stats.vport; struct mlx5e_pport_stats *pstats = &priv->stats.pport; - if (!mlx5e_monitor_counter_supported(priv)) { + /* In switchdev mode, monitor counters doesn't monitor + * rx/tx stats of 802_3. The update stats mechanism + * should keep the 802_3 layout counters updated + */ + if (!mlx5e_monitor_counter_supported(priv) || + mlx5e_is_uplink_rep(priv)) { /* update HW stats in background for next time */ mlx5e_queue_update_stats(priv); } Patches currently in stable-queue which might be from yanjunz@xxxxxxxxxxxx are queue-5.6/net-mlx5e-get-the-latest-values-from-counters-in-switchdev-mode.patch