[PATCH 5.10 042/120] net/mlx5e: Update max_opened_tc also when channels are closed

From: Greg Kroah-Hartman
Date: Mon Feb 08 2021 - 12:07:54 EST


From: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>

[ Upstream commit 5a2ba25a55c4dc0f143567c99aede768b6628ebd ]

max_opened_tc is used for stats, so that potentially non-zero stats
won't disappear when num_tc decreases. However, mlx5e_setup_tc_mqprio
fails to update it in the flow where channels are closed.

This commit fixes it. The new value of priv->channels.params.num_tc is
always checked on exit. In case of errors it will just be the old value,
and in case of success it will be the updated value.

Fixes: 05909babce53 ("net/mlx5e: Avoid reset netdev stats on configuration changes")
Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index c9b5d7f29911e..42848db8f8dd6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3593,12 +3593,10 @@ static int mlx5e_setup_tc_mqprio(struct mlx5e_priv *priv,

err = mlx5e_safe_switch_channels(priv, &new_channels,
mlx5e_num_channels_changed_ctx, NULL);
- if (err)
- goto out;

- priv->max_opened_tc = max_t(u8, priv->max_opened_tc,
- new_channels.params.num_tc);
out:
+ priv->max_opened_tc = max_t(u8, priv->max_opened_tc,
+ priv->channels.params.num_tc);
mutex_unlock(&priv->state_lock);
return err;
}
--
2.27.0