{
        struct net_bridge *br = netdev_priv(dev);
 
-       return br_add_if(br, slave_dev);
+       return br_add_if(br, slave_dev, extack);
 }
 
 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 
 }
 
 /* called with RTNL */
-int br_add_if(struct net_bridge *br, struct net_device *dev)
+int br_add_if(struct net_bridge *br, struct net_device *dev,
+             struct netlink_ext_ack *extack)
 {
        struct net_bridge_port *p;
        int err = 0;
                return -EINVAL;
 
        /* No bridging of bridges */
-       if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
+       if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
+               NL_SET_ERR_MSG(extack,
+                              "Can not enslave a bridge to a bridge");
                return -ELOOP;
+       }
 
        /* Device is already being bridged */
        if (br_port_exists(dev))
                return -EBUSY;
 
        /* No bridging devices that dislike that (e.g. wireless) */
-       if (dev->priv_flags & IFF_DONT_BRIDGE)
+       if (dev->priv_flags & IFF_DONT_BRIDGE) {
+               NL_SET_ERR_MSG(extack,
+                              "Device does not allow enslaving to a bridge");
                return -EOPNOTSUPP;
+       }
 
        p = new_nbp(br, dev);
        if (IS_ERR(p))
 
        dev->priv_flags |= IFF_BRIDGE_PORT;
 
-       err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, NULL);
+       err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
        if (err)
                goto err5;
 
 
                return -EINVAL;
 
        if (isadd)
-               ret = br_add_if(br, dev);
+               ret = br_add_if(br, dev, NULL);
        else
                ret = br_del_if(br, dev);
 
 
 void br_port_carrier_check(struct net_bridge_port *p);
 int br_add_bridge(struct net *net, const char *name);
 int br_del_bridge(struct net *net, const char *name);
-int br_add_if(struct net_bridge *br, struct net_device *dev);
+int br_add_if(struct net_bridge *br, struct net_device *dev,
+             struct netlink_ext_ack *extack);
 int br_del_if(struct net_bridge *br, struct net_device *dev);
 int br_min_mtu(const struct net_bridge *br);
 netdev_features_t br_features_recompute(struct net_bridge *br,