This is a note to let you know that I've just added the patch titled net/mlx4_en: update moderation when config reset to the 5.4-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-mlx4_en-update-moderation-when-config-reset.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 00ff801bb8ce6711e919af4530b6ffa14a22390a Mon Sep 17 00:00:00 2001 From: "Kevin(Yudong) Yang" <yyd@xxxxxxxxxx> Date: Wed, 3 Mar 2021 09:43:54 -0500 Subject: net/mlx4_en: update moderation when config reset From: Kevin(Yudong) Yang <yyd@xxxxxxxxxx> commit 00ff801bb8ce6711e919af4530b6ffa14a22390a upstream. This patch fixes a bug that the moderation config will not be applied when calling mlx4_en_reset_config. For example, when turning on rx timestamping, mlx4_en_reset_config() will be called, causing the NIC to forget previous moderation config. This fix is in phase with a previous fix: commit 79c54b6bbf06 ("net/mlx4_en: Fix TX moderation info loss after set_ringparam is called") Tested: Before this patch, on a host with NIC using mlx4, run netserver and stream TCP to the host at full utilization. $ sar -I SUM 1 INTR intr/s 14:03:56 sum 48758.00 After rx hwtstamp is enabled: $ sar -I SUM 1 14:10:38 sum 317771.00 We see the moderation is not working properly and issued 7x more interrupts. After the patch, and turned on rx hwtstamp, the rate of interrupts is as expected: $ sar -I SUM 1 14:52:11 sum 49332.00 Fixes: 79c54b6bbf06 ("net/mlx4_en: Fix TX moderation info loss after set_ringparam is called") Signed-off-by: Kevin(Yudong) Yang <yyd@xxxxxxxxxx> Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reviewed-by: Neal Cardwell <ncardwell@xxxxxxxxxx> CC: Tariq Toukan <tariqt@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlx4/en_ethtool.c | 2 +- drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 2 ++ drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 1 + 3 files changed, 4 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c @@ -47,7 +47,7 @@ #define EN_ETHTOOL_SHORT_MASK cpu_to_be16(0xffff) #define EN_ETHTOOL_WORD_MASK cpu_to_be32(0xffffffff) -static int mlx4_en_moderation_update(struct mlx4_en_priv *priv) +int mlx4_en_moderation_update(struct mlx4_en_priv *priv) { int i, t; int err = 0; --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -3657,6 +3657,8 @@ int mlx4_en_reset_config(struct net_devi en_err(priv, "Failed starting port\n"); } + if (!err) + err = mlx4_en_moderation_update(priv); out: mutex_unlock(&mdev->state_lock); kfree(tmp); --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -797,6 +797,7 @@ void mlx4_en_ptp_overflow_check(struct m #define DEV_FEATURE_CHANGED(dev, new_features, feature) \ ((dev->features & feature) ^ (new_features & feature)) +int mlx4_en_moderation_update(struct mlx4_en_priv *priv); int mlx4_en_reset_config(struct net_device *dev, struct hwtstamp_config ts_config, netdev_features_t new_features); Patches currently in stable-queue which might be from yyd@xxxxxxxxxx are queue-5.4/net-mlx4_en-update-moderation-when-config-reset.patch