net: dsa: make the STP state function return void

The DSA layer doesn't care about the return code of the port_stp_update
routine, so make it void in the layer and the DSA drivers.

Replace the useless dsa_slave_stp_update function with a
dsa_slave_stp_state function used to reply to the switchdev
SWITCHDEV_ATTR_ID_PORT_STP_STATE attribute.

In the meantime, rename port_stp_update to port_stp_state_set to
explicit the state change.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/dsa/dsa.txt

@@ -533,7 +533,7 @@ Bridge layer
   out at the switch hardware for the switch to (re) learn MAC addresses behind
   this port.
 
-- port_stp_update: bridge layer function invoked when a given switch port STP
+- port_stp_state_set: bridge layer function invoked when a given switch port STP
   state is computed by the bridge layer and should be propagated to switch
   hardware to forward/block/learn traffic. The switch driver is responsible for
   computing a STP state change based on current and asked parameters and perform

drivers/net/dsa/bcm_sf2.c

@@ -545,12 +545,11 @@ static void bcm_sf2_sw_br_leave(struct dsa_switch *ds, int port)
 	priv->port_sts[port].bridge_dev = NULL;
 }
 
-static int bcm_sf2_sw_br_set_stp_state(struct dsa_switch *ds, int port,
-				       u8 state)
+static void bcm_sf2_sw_br_set_stp_state(struct dsa_switch *ds, int port,
+					u8 state)
 {
 	struct bcm_sf2_priv *priv = ds_to_priv(ds);
 	u8 hw_state, cur_hw_state;
-	int ret = 0;
 	u32 reg;
 
 	reg = core_readl(priv, CORE_G_PCTL_PORT(port));
@@ -574,7 +573,7 @@ static int bcm_sf2_sw_br_set_stp_state(struct dsa_switch *ds, int port,
 		break;
 	default:
 		pr_err("%s: invalid STP state: %d\n", __func__, state);
-		return -EINVAL;
+		return;
 	}
 
 	/* Fast-age ARL entries if we are moving a port from Learning or
@@ -584,10 +583,9 @@ static int bcm_sf2_sw_br_set_stp_state(struct dsa_switch *ds, int port,
 	if (cur_hw_state != hw_state) {
 		if (cur_hw_state >= G_MISTP_LEARN_STATE &&
 		    hw_state <= G_MISTP_LISTEN_STATE) {
-			ret = bcm_sf2_sw_fast_age_port(ds, port);
-			if (ret) {
+			if (bcm_sf2_sw_fast_age_port(ds, port)) {
 				pr_err("%s: fast-ageing failed\n", __func__);
-				return ret;
+				return;
 			}
 		}
 	}
@@ -596,8 +594,6 @@ static int bcm_sf2_sw_br_set_stp_state(struct dsa_switch *ds, int port,
 	reg &= ~(G_MISTP_STATE_MASK << G_MISTP_STATE_SHIFT);
 	reg |= hw_state;
 	core_writel(priv, reg, CORE_G_PCTL_PORT(port));
-
-	return 0;
 }
 
 /* Address Resolution Logic routines */
@@ -1387,7 +1383,7 @@ static struct dsa_switch_driver bcm_sf2_switch_driver = {
 	.set_eee		= bcm_sf2_sw_set_eee,
 	.port_bridge_join	= bcm_sf2_sw_br_join,
 	.port_bridge_leave	= bcm_sf2_sw_br_leave,
-	.port_stp_update	= bcm_sf2_sw_br_set_stp_state,
+	.port_stp_state_set	= bcm_sf2_sw_br_set_stp_state,
 	.port_fdb_prepare	= bcm_sf2_sw_fdb_prepare,
 	.port_fdb_add		= bcm_sf2_sw_fdb_add,
 	.port_fdb_del		= bcm_sf2_sw_fdb_del,

drivers/net/dsa/mv88e6171.c

@@ -105,7 +105,7 @@ struct dsa_switch_driver mv88e6171_switch_driver = {
 	.get_regs		= mv88e6xxx_get_regs,
 	.port_bridge_join	= mv88e6xxx_port_bridge_join,
 	.port_bridge_leave	= mv88e6xxx_port_bridge_leave,
-	.port_stp_update        = mv88e6xxx_port_stp_update,
+	.port_stp_state_set	= mv88e6xxx_port_stp_state_set,
 	.port_vlan_filtering	= mv88e6xxx_port_vlan_filtering,
 	.port_vlan_prepare	= mv88e6xxx_port_vlan_prepare,
 	.port_vlan_add		= mv88e6xxx_port_vlan_add,

drivers/net/dsa/mv88e6352.c

@@ -326,7 +326,7 @@ struct dsa_switch_driver mv88e6352_switch_driver = {
 	.get_regs		= mv88e6xxx_get_regs,
 	.port_bridge_join	= mv88e6xxx_port_bridge_join,
 	.port_bridge_leave	= mv88e6xxx_port_bridge_leave,
-	.port_stp_update	= mv88e6xxx_port_stp_update,
+	.port_stp_state_set	= mv88e6xxx_port_stp_state_set,
 	.port_vlan_filtering	= mv88e6xxx_port_vlan_filtering,
 	.port_vlan_prepare	= mv88e6xxx_port_vlan_prepare,
 	.port_vlan_add		= mv88e6xxx_port_vlan_add,

drivers/net/dsa/mv88e6xxx.c

@@ -1193,7 +1193,7 @@ static int _mv88e6xxx_port_based_vlan_map(struct dsa_switch *ds, int port)
 	return _mv88e6xxx_reg_write(ds, REG_PORT(port), PORT_BASE_VLAN, reg);
 }
 
-int mv88e6xxx_port_stp_update(struct dsa_switch *ds, int port, u8 state)
+void mv88e6xxx_port_stp_state_set(struct dsa_switch *ds, int port, u8 state)
 {
 	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
 	int stp_state;
@@ -1215,14 +1215,12 @@ int mv88e6xxx_port_stp_update(struct dsa_switch *ds, int port, u8 state)
 		break;
 	}
 
-	/* mv88e6xxx_port_stp_update may be called with softirqs disabled,
+	/* mv88e6xxx_port_stp_state_set may be called with softirqs disabled,
 	 * so we can not update the port state directly but need to schedule it.
 	 */
 	ps->ports[port].state = stp_state;
 	set_bit(port, ps->port_state_update_mask);
 	schedule_work(&ps->bridge_work);
-
-	return 0;
 }
 
 static int _mv88e6xxx_port_pvid(struct dsa_switch *ds, int port, u16 *new,

drivers/net/dsa/mv88e6xxx.h

@@ -497,7 +497,7 @@ int mv88e6xxx_set_eee(struct dsa_switch *ds, int port,
 int mv88e6xxx_port_bridge_join(struct dsa_switch *ds, int port,
 			       struct net_device *bridge);
 void mv88e6xxx_port_bridge_leave(struct dsa_switch *ds, int port);
-int mv88e6xxx_port_stp_update(struct dsa_switch *ds, int port, u8 state);
+void mv88e6xxx_port_stp_state_set(struct dsa_switch *ds, int port, u8 state);
 int mv88e6xxx_port_vlan_filtering(struct dsa_switch *ds, int port,
 				  bool vlan_filtering);
 int mv88e6xxx_port_vlan_prepare(struct dsa_switch *ds, int port,

include/net/dsa.h

@@ -299,8 +299,8 @@ struct dsa_switch_driver {
 	int	(*port_bridge_join)(struct dsa_switch *ds, int port,
 				    struct net_device *bridge);
 	void	(*port_bridge_leave)(struct dsa_switch *ds, int port);
-	int	(*port_stp_update)(struct dsa_switch *ds, int port,
-				   u8 state);
+	void	(*port_stp_state_set)(struct dsa_switch *ds, int port,
+				      u8 state);
 
 	/*
 	 * VLAN support

net/dsa/slave.c

@@ -104,8 +104,8 @@ static int dsa_slave_open(struct net_device *dev)
 			goto clear_promisc;
 	}
 
-	if (ds->drv->port_stp_update)
-		ds->drv->port_stp_update(ds, p->port, stp_state);
+	if (ds->drv->port_stp_state_set)
+		ds->drv->port_stp_state_set(ds, p->port, stp_state);
 
 	if (p->phy)
 		phy_start(p->phy);
@@ -147,8 +147,8 @@ static int dsa_slave_close(struct net_device *dev)
 	if (ds->drv->port_disable)
 		ds->drv->port_disable(ds, p->port, p->phy);
 
-	if (ds->drv->port_stp_update)
-		ds->drv->port_stp_update(ds, p->port, BR_STATE_DISABLED);
+	if (ds->drv->port_stp_state_set)
+		ds->drv->port_stp_state_set(ds, p->port, BR_STATE_DISABLED);
 
 	return 0;
 }
@@ -305,16 +305,19 @@ static int dsa_slave_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	return -EOPNOTSUPP;
 }
 
-static int dsa_slave_stp_update(struct net_device *dev, u8 state)
+static int dsa_slave_stp_state_set(struct net_device *dev,
+				   const struct switchdev_attr *attr,
+				   struct switchdev_trans *trans)
 {
 	struct dsa_slave_priv *p = netdev_priv(dev);
 	struct dsa_switch *ds = p->parent;
-	int ret = -EOPNOTSUPP;
 
-	if (ds->drv->port_stp_update)
-		ret = ds->drv->port_stp_update(ds, p->port, state);
+	if (switchdev_trans_ph_prepare(trans))
+		return ds->drv->port_stp_state_set ? 0 : -EOPNOTSUPP;
 
-	return ret;
+	ds->drv->port_stp_state_set(ds, p->port, attr->u.stp_state);
+
+	return 0;
 }
 
 static int dsa_slave_vlan_filtering(struct net_device *dev,
@@ -339,17 +342,11 @@ static int dsa_slave_port_attr_set(struct net_device *dev,
 				   const struct switchdev_attr *attr,
 				   struct switchdev_trans *trans)
 {
-	struct dsa_slave_priv *p = netdev_priv(dev);
-	struct dsa_switch *ds = p->parent;
 	int ret;
 
 	switch (attr->id) {
 	case SWITCHDEV_ATTR_ID_PORT_STP_STATE:
-		if (switchdev_trans_ph_prepare(trans))
-			ret = ds->drv->port_stp_update ? 0 : -EOPNOTSUPP;
-		else
-			ret = ds->drv->port_stp_update(ds, p->port,
-						       attr->u.stp_state);
+		ret = dsa_slave_stp_state_set(dev, attr, trans);
 		break;
 	case SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING:
 		ret = dsa_slave_vlan_filtering(dev, attr, trans);
@@ -468,7 +465,8 @@ static void dsa_slave_bridge_port_leave(struct net_device *dev)
 	/* Port left the bridge, put in BR_STATE_DISABLED by the bridge layer,
 	 * so allow it to be in BR_STATE_FORWARDING to be kept functional
 	 */
-	dsa_slave_stp_update(dev, BR_STATE_FORWARDING);
+	if (ds->drv->port_stp_state_set)
+		ds->drv->port_stp_state_set(ds, p->port, BR_STATE_FORWARDING);
 }
 
 static int dsa_slave_port_attr_get(struct net_device *dev,