Subject: [net 3/4] net/mlx5e: Update max_opened_tc also when channels are closed

From: Saeed Mahameed <[email-masked]>
Date: Mon, 1 Feb 2021 23:07:02 -0800

From: Maxim Mikityanskiy <[email-masked]>

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 <[email-masked]>
Reviewed-by: Tariq Toukan <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 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 a9d824a9cb05..3fc7d18ac868 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -3627,12 +3627,10 @@ 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;
 }
-- 
2.29.2