+static void br_stp_start(struct net_bridge *br)
+{
+ int r;
+ char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
+ char *envp[] = { NULL };
+
+ r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+ if (r == 0) {
+ br->stp_enabled = BR_USER_STP;
+ printk(KERN_INFO "%s: userspace STP started\n", br->dev->name);
+ } else {
+ br->stp_enabled = BR_KERNEL_STP;
+ printk(KERN_INFO "%s: starting userspace STP failed, "
+ "starting kernel STP\n", br->dev->name);
+
+ /* To start timers on any ports left in blocking */
+ spin_lock_bh(&br->lock);
+ br_port_state_selection(br);
+ spin_unlock_bh(&br->lock);
+ }
+}
+
+static void br_stp_stop(struct net_bridge *br)
+{
+ int r;
+ char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
+ char *envp[] = { NULL };
+
+ if (br->stp_enabled == BR_USER_STP) {
+ r = call_usermodehelper(BR_STP_PROG, argv, envp, 1);
+ printk(KERN_INFO "%s: userspace STP stopped, return code %d\n",
+ br->dev->name, r);
+
+
+ /* To start timers on any ports left in blocking */
+ spin_lock_bh(&br->lock);
+ br_port_state_selection(br);
+ spin_unlock_bh(&br->lock);
+ }
+
+ br->stp_enabled = BR_NO_STP;
+}
+
+void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
+{
+ ASSERT_RTNL();
+
+ if (val) {
+ if (br->stp_enabled == BR_NO_STP)
+ br_stp_start(br);
+ } else {
+ if (br->stp_enabled != BR_NO_STP)
+ br_stp_stop(br);
+ }
+}
+