From: Maxim Mikityanskiy <maximmi@mellanox.com>
Date: Thu, 14 Jan 2021 12:34:01 +0200
Subject: net/mlx5e: Revert parameters on errors when changing trust state
 without reset
Patch-mainline: v5.11-rc6
Git-commit: 8355060f5ec381abda77659f91f56302203df535
References: jsc#SLE-15172

Trust state may be changed without recreating the channels. It happens
when the channels are closed, and when channel parameters (min inline
mode) stay the same after changing the trust state. Changing the trust
state is a hardware command that may fail. The current code didn't
restore the channel parameters to their old values if an error happened
and the channels were closed. This commit adds handling for this case.

Fixes: 6e0504c69811 ("net/mlx5e: Change inline mode correctly when changing trust state")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
@@ -1151,6 +1151,7 @@ static int mlx5e_set_trust_state(struct
 {
 	struct mlx5e_channels new_channels = {};
 	bool reset_channels = true;
+	bool opened;
 	int err = 0;
 
 	mutex_lock(&priv->state_lock);
@@ -1159,22 +1160,24 @@ static int mlx5e_set_trust_state(struct
 	mlx5e_params_calc_trust_tx_min_inline_mode(priv->mdev, &new_channels.params,
 						   trust_state);
 
-	if (!test_bit(MLX5E_STATE_OPENED, &priv->state)) {
-		priv->channels.params = new_channels.params;
+	opened = test_bit(MLX5E_STATE_OPENED, &priv->state);
+	if (!opened)
 		reset_channels = false;
-	}
 
 	/* Skip if tx_min_inline is the same */
 	if (new_channels.params.tx_min_inline_mode ==
 	    priv->channels.params.tx_min_inline_mode)
 		reset_channels = false;
 
-	if (reset_channels)
+	if (reset_channels) {
 		err = mlx5e_safe_switch_channels(priv, &new_channels,
 						 mlx5e_update_trust_state_hw,
 						 &trust_state);
-	else
+	} else {
 		err = mlx5e_update_trust_state_hw(priv, &trust_state);
+		if (!err && !opened)
+			priv->channels.params = new_channels.params;
+	}
 
 	mutex_unlock(&priv->state_lock);