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net/mlx5e: Update netdev features only after a successful ringparam set

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mlx5 couples HW-GRO with tcp-data-split. If a user sets rx-gro-hw on ->
tcp-data-split on -> rx-gro-hw off, the driver will leave HW-GRO on.
mlx5e_ethtool_set_tcp_data_split() calls netdev_update_features() when
tcp-data-split goes from enabled to disabled in case HW-GRO needs to be
released. mlx5e_fix_features() reads the new HDS config from
dev->cfg_pending, so HW-GRO is released before all ring parameters are
validated.

If the subsequent call to mlx5e_ethtool_set_ringparam() fails, the
ethtool core discards the pending change and reports tcp-data-split
enabled. The device is no longer splitting, and subsequent ring changes
are blocked.

Move the call to netdev_update_features() after
mlx5e_ethtool_set_ringparam() exits successfully.

The issue was discovered by manual code inspection during review of
a change that stops mlx5 users from disabling tcp-data-split. It was
reproduced on a ConnectX-7 with ethtool alone.

Steps to reproduce:
ethtool -K eth0 rx-gro-hw on
ethtool -G eth0 tcp-data-split on
ethtool -K eth0 rx-gro-hw off # HW-GRO kept on for tcp-data-split

ethtool -G eth0 tcp-data-split off rx 1 # de-sync driver & kernel state
 netlink error: mlx5_core: rx (1) < min (16)
 netlink error: Invalid argument

ethtool -G eth0 rx 1024 # valid ring changes are now blocked
 netlink error: mlx5_core: TCP-data-split is not supported when GRO HW is disabled
 netlink error: Invalid argument

This is not a terminal state, users can recover by setting rx-gro-hw on.
With the fix, the failing ringparam set leaves rx-gro-hw on and later
ring changes succeed.

Fixes: 46bcce5dfd ("net/mlx5e: Support ethtool tcp-data-split settings")
Reported-by: Björn Töpel <bjorn@kernel.org>
Closes: https://lore.kernel.org/87se2grw3d.fsf@all.your.base.are.belong.to.us/
Signed-off-by: Dimitri Daskalakis <daskald@meta.com>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Acked-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20261017005401.1582755-1-dimitri.daskalakis1@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Dimitri Daskalakis 2026-10-16 17:54:01 -07:00 committed by Jakub Kicinski
parent f434191f93
commit 23dd5be7e1
1 changed files with 11 additions and 6 deletions
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17
drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
View File

@ -403,11 +403,6 @@ static bool mlx5e_ethtool_set_tcp_data_split(struct mlx5e_priv *priv,
return false;
}
/* Might need to disable HW-GRO if it was kept on due to hds. */
if (tcp_data_split == ETHTOOL_TCP_DATA_SPLIT_DISABLED &&
dev->cfg->hds_config == ETHTOOL_TCP_DATA_SPLIT_ENABLED)
netdev_update_features(priv->netdev);
return true;
}
@ -468,13 +463,23 @@ static int mlx5e_set_ringparam(struct net_device *dev,
struct netlink_ext_ack *extack)
{
struct mlx5e_priv *priv = netdev_priv(dev);
int err;
if (!mlx5e_ethtool_set_tcp_data_split(priv,
kernel_param->tcp_data_split,
extack))
return -EINVAL;
return mlx5e_ethtool_set_ringparam(priv, param, extack);
err = mlx5e_ethtool_set_ringparam(priv, param, extack);
if (err)
return err;
/* Might need to disable HW-GRO if it was kept on due to hds. */
if (kernel_param->tcp_data_split == ETHTOOL_TCP_DATA_SPLIT_DISABLED &&
dev->cfg->hds_config == ETHTOOL_TCP_DATA_SPLIT_ENABLED)
netdev_update_features(priv->netdev);
return 0;
}
void mlx5e_ethtool_get_channels(struct mlx5e_priv *priv,