net/mlx5e: Optimization for MTU change

Avoid unnecessary interface down/up operations upon an MTU change
when it does not affect the rings configuration.

Fixes: 461017cb006a ("net/mlx5e: Support RX multi-packet WQE (Striding RQ)")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 0fc3a2b..65258b2 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -2569,6 +2569,7 @@ static int mlx5e_change_mtu(struct net_device *netdev, int new_mtu)
        u16 max_mtu;
        u16 min_mtu;
        int err = 0;
+       bool reset;
 
        mlx5_query_port_max_mtu(mdev, &max_mtu, 1);
 
@@ -2584,14 +2585,18 @@ static int mlx5e_change_mtu(struct net_device *netdev, int new_mtu)
 
        mutex_lock(&priv->state_lock);
 
+       reset = !priv->params.lro_en &&
+               (priv->params.rq_wq_type !=
+                MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ);
+
        was_opened = test_bit(MLX5E_STATE_OPENED, &priv->state);
-       if (was_opened)
+       if (was_opened && reset)
                mlx5e_close_locked(netdev);
 
        netdev->mtu = new_mtu;
        mlx5e_set_dev_port_mtu(netdev);
 
-       if (was_opened)
+       if (was_opened && reset)
                err = mlx5e_open_locked(netdev);
 
        mutex_unlock(&priv->state_lock);