net: dsa: fix preparation of a port STP update

Because of the default 0 value of ret in dsa_slave_port_attr_set, a driver may return -EOPNOTSUPP from the commit phase of a STP state, which triggers a WARN() from switchdev. This happened on a 6185 switch which does not support hardware bridging. Fixes: 3563606 ("switchdev: convert STP update to switchdev attr set") Reported-by: Andrew Lunn <[email protected]> Signed-off-by: Vivien Didelot <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · Sep 30, 2015 · 57a4753 · 57a4753
1 parent 9ae6d49
commit 57a4753
Showing 1 changed file with 8 additions and 3 deletions.
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
@@ -458,12 +458,17 @@ static int dsa_slave_stp_update(struct net_device *dev, u8 state)
 static int dsa_slave_port_attr_set(struct net_device *dev,
 				   struct switchdev_attr *attr)
 {
-	int ret = 0;
+	struct dsa_slave_priv *p = netdev_priv(dev);
+	struct dsa_switch *ds = p->parent;
+	int ret;
 
 	switch (attr->id) {
 	case SWITCHDEV_ATTR_PORT_STP_STATE:
-		if (attr->trans == SWITCHDEV_TRANS_COMMIT)
-			ret = dsa_slave_stp_update(dev, attr->u.stp_state);
+		if (attr->trans == SWITCHDEV_TRANS_PREPARE)
+			ret = ds->drv->port_stp_update ? 0 : -EOPNOTSUPP;
+		else
+			ret = ds->drv->port_stp_update(ds, p->port,
+						       attr->u.stp_state);
 		break;
 	default:
 		ret = -EOPNOTSUPP;