return (dev->qdisc != &noop_qdisc);
 }
 
+/* Check if a route is valid prefix route */
+static inline int addrconf_is_prefix_route(const struct rt6_info *rt)
+{
+       return ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0);
+}
+
 static void addrconf_del_timer(struct inet6_ifaddr *ifp)
 {
        if (del_timer(&ifp->timer))
                ipv6_addr_prefix(&prefix, &ifp->addr, ifp->prefix_len);
                rt = rt6_lookup(net, &prefix, NULL, ifp->idev->dev->ifindex, 1);
 
-               if (rt && ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0)) {
+               if (rt && addrconf_is_prefix_route(rt)) {
                        if (onlink == 0) {
                                ip6_del_rt(rt);
                                rt = NULL;
                rt = rt6_lookup(dev_net(dev), &pinfo->prefix, NULL,
                                dev->ifindex, 1);
 
-               if (rt && ((rt->rt6i_flags & (RTF_GATEWAY | RTF_DEFAULT)) == 0)) {
+               if (rt && addrconf_is_prefix_route(rt)) {
                        /* Autoconf prefix route */
                        if (valid_lft == 0) {
                                ip6_del_rt(rt);