net/mlx5e: Don't change interrupt moderation params when DIM is enabled

[ Upstream commit 019f93b ]

When mlx5e_ethtool_set_coalesce doesn't change DIM state
(enabled/disabled), it calls mlx5e_set_priv_channels_coalesce
unconditionally, which in turn invokes a firmware command to set
interrupt moderation parameters. It shouldn't happen while DIM manages
those parameters dynamically (it might even be happening at the same
time).

This patch fixes it by splitting mlx5e_set_priv_channels_coalesce into
two functions (for RX and TX) and calling them only when DIM is disabled
(for RX and TX respectively).

Fixes: cb3c7fd ("net/mlx5e: Support adaptive RX coalescing")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Maxim Mikityanskiy

drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c

@@ -522,7 +522,7 @@ static int mlx5e_get_coalesce(struct net_device *netdev,
 #define MLX5E_MAX_COAL_FRAMES		MLX5_MAX_CQ_COUNT
 
 static void
-mlx5e_set_priv_channels_coalesce(struct mlx5e_priv *priv, struct ethtool_coalesce *coal)
+mlx5e_set_priv_channels_tx_coalesce(struct mlx5e_priv *priv, struct ethtool_coalesce *coal)
 {
 	struct mlx5_core_dev *mdev = priv->mdev;
 	int tc;
@@ -537,6 +537,17 @@ mlx5e_set_priv_channels_coalesce(struct mlx5e_priv *priv, struct ethtool_coalesc
 						coal->tx_coalesce_usecs,
 						coal->tx_max_coalesced_frames);
 		}
+	}
+}
+
+static void
+mlx5e_set_priv_channels_rx_coalesce(struct mlx5e_priv *priv, struct ethtool_coalesce *coal)
+{
+	struct mlx5_core_dev *mdev = priv->mdev;
+	int i;
+
+	for (i = 0; i < priv->channels.num; ++i) {
+		struct mlx5e_channel *c = priv->channels.c[i];
 
 		mlx5_core_modify_cq_moderation(mdev, &c->rq.cq.mcq,
 					       coal->rx_coalesce_usecs,
@@ -593,7 +604,10 @@ int mlx5e_ethtool_set_coalesce(struct mlx5e_priv *priv,
 	reset_tx = !!coal->use_adaptive_tx_coalesce != priv->channels.params.tx_dim_enabled;
 
 	if (!reset_rx && !reset_tx) {
-		mlx5e_set_priv_channels_coalesce(priv, coal);
+		if (!coal->use_adaptive_rx_coalesce)
+			mlx5e_set_priv_channels_rx_coalesce(priv, coal);
+		if (!coal->use_adaptive_tx_coalesce)
+			mlx5e_set_priv_channels_tx_coalesce(priv, coal);
 		priv->channels.params = new_channels.params;
 		goto out;
 	}