2 files changed, 21 insertions, 5 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 4186e29119c2..a68e62256bee 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -590,21 +590,28 @@ static int mlxsw_sp_port_dev_addr_init(struct mlxsw_sp_port *mlxsw_sp_port)
 	return mlxsw_sp_port_dev_addr_set(mlxsw_sp_port, addr);
 }
 
-static int mlxsw_sp_port_mtu_set(struct mlxsw_sp_port *mlxsw_sp_port, u16 mtu)
+static int mlxsw_sp_port_max_mtu_get(struct mlxsw_sp_port *mlxsw_sp_port, int *p_max_mtu)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
 	char pmtu_pl[MLXSW_REG_PMTU_LEN];
-	int max_mtu;
 	int err;
 
-	mtu += MLXSW_TXHDR_LEN + ETH_HLEN;
 	mlxsw_reg_pmtu_pack(pmtu_pl, mlxsw_sp_port->local_port, 0);
 	err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(pmtu), pmtu_pl);
 	if (err)
 		return err;
-	max_mtu = mlxsw_reg_pmtu_max_mtu_get(pmtu_pl);
 
-	if (mtu > max_mtu)
+	*p_max_mtu = mlxsw_reg_pmtu_max_mtu_get(pmtu_pl);
+	return 0;
+}
+
+static int mlxsw_sp_port_mtu_set(struct mlxsw_sp_port *mlxsw_sp_port, u16 mtu)
+{
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	char pmtu_pl[MLXSW_REG_PMTU_LEN];
+
+	mtu += MLXSW_TXHDR_LEN + ETH_HLEN;
+	if (mtu > mlxsw_sp_port->max_mtu)
 		return -EINVAL;
 
 	mlxsw_reg_pmtu_pack(pmtu_pl, mlxsw_sp_port->local_port, mtu);
@@ -1842,6 +1849,13 @@ static int mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 		goto err_port_speed_by_width_set;
 	}
 
+	err = mlxsw_sp_port_max_mtu_get(mlxsw_sp_port, &mlxsw_sp_port->max_mtu);
+	if (err) {
+		dev_err(mlxsw_sp->bus_info->dev, "Port %d: Failed to get maximum MTU\n",
+			mlxsw_sp_port->local_port);
+		goto err_port_max_mtu_get;
+	}
+
 	err = mlxsw_sp_port_mtu_set(mlxsw_sp_port, ETH_DATA_LEN);
 	if (err) {
 		dev_err(mlxsw_sp->bus_info->dev, "Port %d: Failed to set MTU\n",
@@ -1966,6 +1980,7 @@ err_port_ets_init:
 err_port_buffers_init:
 err_port_admin_status_set:
 err_port_mtu_set:
+err_port_max_mtu_get:
 err_port_speed_by_width_set:
 err_port_system_port_mapping_set:
 err_dev_addr_init:
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
index 007e97e99ec8..69e59cf7812f 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
@@ -319,6 +319,7 @@ struct mlxsw_sp_port {
 	struct {
 		struct delayed_work speed_update_dw;
 	} span;
+	int max_mtu;
 };
 
 struct mlxsw_sp_port_type_speed_ops {