mlxsw: spectrum: Make split flow match firmware requirements

When a port is created following a split / unsplit we need to map it to
the correct module and lane, enable it and then continue to initialize
its various parameters such as MTU and VLAN filters.

Under certain conditions, such as trying to split ports at the bottom
row of the front panel by four, we get firmware errors.

After evaluating this with the firmware team it was decided to alter the
split / unsplit flow, so that first all the affected ports are mapped,
then enabled and finally each is initialized separately.

Fix the split / unsplit flow by first mapping and enabling all the
affected ports. Newer firmware versions will support both flows.

Fixes: 18f1e70c41 ("mlxsw: spectrum: Introduce port splitting")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -247,13 +247,21 @@ static int mlxsw_sp_port_mtu_set(struct mlxsw_sp_port *mlxsw_sp_port, u16 mtu)
 	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(pmtu), pmtu_pl);
 }
 
+static int __mlxsw_sp_port_swid_set(struct mlxsw_sp *mlxsw_sp, u8 local_port,
+				    u8 swid)
+{
+	char pspa_pl[MLXSW_REG_PSPA_LEN];
+
+	mlxsw_reg_pspa_pack(pspa_pl, swid, local_port);
+	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(pspa), pspa_pl);
+}
+
 static int mlxsw_sp_port_swid_set(struct mlxsw_sp_port *mlxsw_sp_port, u8 swid)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
-	char pspa_pl[MLXSW_REG_PSPA_LEN];
 
-	mlxsw_reg_pspa_pack(pspa_pl, swid, mlxsw_sp_port->local_port);
+	return __mlxsw_sp_port_swid_set(mlxsw_sp, mlxsw_sp_port->local_port,
-	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(pspa), pspa_pl);
+					swid);
 }
 
 static int mlxsw_sp_port_vp_mode_set(struct mlxsw_sp_port *mlxsw_sp_port,
@@ -1681,8 +1689,8 @@ static int mlxsw_sp_port_ets_init(struct mlxsw_sp_port *mlxsw_sp_port)
 	return 0;
 }
 
-static int __mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
+static int mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
-				  bool split, u8 module, u8 width)
+				bool split, u8 module, u8 width)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	struct net_device *dev;
@@ -1839,28 +1847,6 @@ static int __mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 	return err;
 }
 
-static int mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
-				bool split, u8 module, u8 width, u8 lane)
-{
-	int err;
-
-	err = mlxsw_sp_port_module_map(mlxsw_sp, local_port, module, width,
-				       lane);
-	if (err)
-		return err;
-
-	err = __mlxsw_sp_port_create(mlxsw_sp, local_port, split, module,
-				     width);
-	if (err)
-		goto err_port_create;
-
-	return 0;
-
-err_port_create:
-	mlxsw_sp_port_module_unmap(mlxsw_sp, local_port);
-	return err;
-}
-
 static void mlxsw_sp_port_vports_fini(struct mlxsw_sp_port *mlxsw_sp_port)
 {
 	struct net_device *dev = mlxsw_sp_port->dev;
@@ -1927,7 +1913,7 @@ static int mlxsw_sp_ports_create(struct mlxsw_sp *mlxsw_sp)
 		if (!width)
 			continue;
 		mlxsw_sp->port_to_module[i] = module;
-		err = __mlxsw_sp_port_create(mlxsw_sp, i, false, module, width);
+		err = mlxsw_sp_port_create(mlxsw_sp, i, false, module, width);
 		if (err)
 			goto err_port_create;
 	}
@@ -1948,12 +1934,85 @@ static u8 mlxsw_sp_cluster_base_port_get(u8 local_port)
 	return local_port - offset;
 }
 
+static int mlxsw_sp_port_split_create(struct mlxsw_sp *mlxsw_sp, u8 base_port,
+				      u8 module, unsigned int count)
+{
+	u8 width = MLXSW_PORT_MODULE_MAX_WIDTH / count;
+	int err, i;
+
+	for (i = 0; i < count; i++) {
+		err = mlxsw_sp_port_module_map(mlxsw_sp, base_port + i, module,
+					       width, i * width);
+		if (err)
+			goto err_port_module_map;
+	}
+
+	for (i = 0; i < count; i++) {
+		err = __mlxsw_sp_port_swid_set(mlxsw_sp, base_port + i, 0);
+		if (err)
+			goto err_port_swid_set;
+	}
+
+	for (i = 0; i < count; i++) {
+		err = mlxsw_sp_port_create(mlxsw_sp, base_port + i, true,
+					   module, width);
+		if (err)
+			goto err_port_create;
+	}
+
+	return 0;
+
+err_port_create:
+	for (i--; i >= 0; i--)
+		mlxsw_sp_port_remove(mlxsw_sp, base_port + i);
+	i = count;
+err_port_swid_set:
+	for (i--; i >= 0; i--)
+		__mlxsw_sp_port_swid_set(mlxsw_sp, base_port + i,
+					 MLXSW_PORT_SWID_DISABLED_PORT);
+	i = count;
+err_port_module_map:
+	for (i--; i >= 0; i--)
+		mlxsw_sp_port_module_unmap(mlxsw_sp, base_port + i);
+	return err;
+}
+
+static void mlxsw_sp_port_unsplit_create(struct mlxsw_sp *mlxsw_sp,
+					 u8 base_port, unsigned int count)
+{
+	u8 local_port, module, width = MLXSW_PORT_MODULE_MAX_WIDTH;
+	int i;
+
+	/* Split by four means we need to re-create two ports, otherwise
+	 * only one.
+	 */
+	count = count / 2;
+
+	for (i = 0; i < count; i++) {
+		local_port = base_port + i * 2;
+		module = mlxsw_sp->port_to_module[local_port];
+
+		mlxsw_sp_port_module_map(mlxsw_sp, local_port, module, width,
+					 0);
+	}
+
+	for (i = 0; i < count; i++)
+		__mlxsw_sp_port_swid_set(mlxsw_sp, base_port + i * 2, 0);
+
+	for (i = 0; i < count; i++) {
+		local_port = base_port + i * 2;
+		module = mlxsw_sp->port_to_module[local_port];
+
+		mlxsw_sp_port_create(mlxsw_sp, local_port, false, module,
+				     width);
+	}
+}
+
 static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u8 local_port,
 			       unsigned int count)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	struct mlxsw_sp_port *mlxsw_sp_port;
-	u8 width = MLXSW_PORT_MODULE_MAX_WIDTH / count;
 	u8 module, cur_width, base_port;
 	int i;
 	int err;
@@ -2001,25 +2060,16 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u8 local_port,
 	for (i = 0; i < count; i++)
 		mlxsw_sp_port_remove(mlxsw_sp, base_port + i);
 
-	for (i = 0; i < count; i++) {
+	err = mlxsw_sp_port_split_create(mlxsw_sp, base_port, module, count);
-		err = mlxsw_sp_port_create(mlxsw_sp, base_port + i, true,
+	if (err) {
-					   module, width, i * width);
+		dev_err(mlxsw_sp->bus_info->dev, "Failed to create split ports\n");
-		if (err) {
+		goto err_port_split_create;
-			dev_err(mlxsw_sp->bus_info->dev, "Failed to create split port\n");
-			goto err_port_create;
-		}
 	}
 
 	return 0;
 
-err_port_create:
+err_port_split_create:
-	for (i--; i >= 0; i--)
+	mlxsw_sp_port_unsplit_create(mlxsw_sp, base_port, count);
-		mlxsw_sp_port_remove(mlxsw_sp, base_port + i);
-	for (i = 0; i < count / 2; i++) {
-		module = mlxsw_sp->port_to_module[base_port + i * 2];
-		mlxsw_sp_port_create(mlxsw_sp, base_port + i * 2, false,
-				     module, MLXSW_PORT_MODULE_MAX_WIDTH, 0);
-	}
 	return err;
 }
 
@@ -2061,14 +2111,7 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u8 local_port)
 	for (i = 0; i < count; i++)
 		mlxsw_sp_port_remove(mlxsw_sp, base_port + i);
 
-	for (i = 0; i < count / 2; i++) {
+	mlxsw_sp_port_unsplit_create(mlxsw_sp, base_port, count);
-		module = mlxsw_sp->port_to_module[base_port + i * 2];
-		err = mlxsw_sp_port_create(mlxsw_sp, base_port + i * 2, false,
-					   module, MLXSW_PORT_MODULE_MAX_WIDTH,
-					   0);
-		if (err)
-			dev_err(mlxsw_sp->bus_info->dev, "Failed to reinstantiate port\n");
-	}
 
 	return 0;
 }