[PATCH net 3/3] net/mlx5: E-Switch, preserve max tx speed on vport state modification

[Tariq Toukan <tariqt@nvidia.com>]

From: Or Har-Toov <ohartoov@nvidia.com>

When modifying vport state, the firmware interprets a zero in the max tx
speed field as an intentional reset, which can overwrite previously set
values. This patch attempts to fix this by querying the current max tx
speed from firmware before modifying the vport state and passing it back
in the modification command. If the query fails, fall back to the cached
agg_max_tx_speed value to avoid inadvertently resetting the speed.

Fixes: 50f1d188c580 ("net/mlx5: Propagate LAG effective max_tx_speed to vports")
Signed-off-by: Or Har-Toov <ohartoov@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Shay Drori <shayd@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../mellanox/mlx5/core/esw/adj_vport.c        | 20 ++++++++++++++++
 .../net/ethernet/mellanox/mlx5/core/vport.c   | 24 +++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/adj_vport.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/adj_vport.c
index 3624c680a861..7950b82d8b8a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/adj_vport.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/adj_vport.c
@@ -11,6 +11,26 @@ int mlx5_esw_adj_vport_modify(struct mlx5_core_dev *dev, u16 vport,
 
 	lockdep_assert_held(&dev->priv.eswitch->state_lock);
 
+	if (MLX5_CAP_ESW(dev, esw_vport_state_max_tx_speed)) {
+		u8 op_mod = MLX5_VPORT_STATE_OP_MOD_ESW_VPORT;
+		struct mlx5_vport *esw_vport;
+		u32 speed = 0;
+		int err;
+
+		err = mlx5_query_vport_max_tx_speed(dev, op_mod, vport,
+						    true, &speed, NULL);
+		if (err) {
+			esw_vport = mlx5_eswitch_get_vport(dev->priv.eswitch,
+							   vport);
+			speed = IS_ERR(esw_vport) ? 0 :
+				esw_vport->agg_max_tx_speed;
+			mlx5_core_dbg(dev,
+				      "Failed to query vport %d max tx speed, err=%d, using cached %u\n",
+				      vport, err, speed);
+		}
+		MLX5_SET(modify_vport_state_in, in, max_tx_speed, speed);
+	}
+
 	MLX5_SET(modify_vport_state_in, in, opcode,
 		 MLX5_CMD_OP_MODIFY_VPORT_STATE);
 	MLX5_SET(modify_vport_state_in, in, op_mod,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/vport.c b/drivers/net/ethernet/mellanox/mlx5/core/vport.c
index edac2d694e0f..8aa94ec87a0e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/vport.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/vport.c
@@ -93,6 +93,30 @@ int mlx5_modify_vport_admin_state(struct mlx5_core_dev *mdev, u8 opmod,
 	lockdep_assert_held(&mdev->priv.eswitch->state_lock);
 #endif
 
+	if (MLX5_CAP_ESW(mdev, esw_vport_state_max_tx_speed) &&
+	    opmod == MLX5_VPORT_STATE_OP_MOD_ESW_VPORT &&
+	    vport != MLX5_VPORT_UPLINK) {
+		u32 speed = 0;
+		int err;
+
+		err = mlx5_query_vport_max_tx_speed(mdev, opmod, vport,
+						    other_vport, &speed, NULL);
+		if (err) {
+#ifdef CONFIG_MLX5_ESWITCH
+			struct mlx5_vport *esw_vport;
+
+			esw_vport = mlx5_eswitch_get_vport(mdev->priv.eswitch,
+							   vport);
+			speed = IS_ERR(esw_vport) ? 0 :
+				esw_vport->agg_max_tx_speed;
+#endif
+			mlx5_core_dbg(mdev,
+				      "Failed to query vport %d max tx speed, err=%d, using cached %u\n",
+				      vport, err, speed);
+		}
+		MLX5_SET(modify_vport_state_in, in, max_tx_speed, speed);
+	}
+
 	MLX5_SET(modify_vport_state_in, in, opcode,
 		 MLX5_CMD_OP_MODIFY_VPORT_STATE);
 	MLX5_SET(modify_vport_state_in, in, op_mod, opmod);
-- 
2.44.0