mac80211: fix mesh sta teardown

The patch "mac80211: clean up mesh sta allocation warning"
moved some mesh initialization into a path which is only
called when the kernel handles peering. This causes a hang
when mac80211 tries to clean up a userspace-allocated
station entry and delete a timer which has never been
initialized.

To avoid this, only do any mesh sta peering teardown if
the kernel is actually handling it.

The same is true when quiescing before suspend.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index 67524e7..56c9b31 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -214,7 +214,7 @@
  *
  * All mesh paths with this peer as next hop will be flushed
  */
-void mesh_plink_deactivate(struct sta_info *sta)
+u32 mesh_plink_deactivate(struct sta_info *sta)
 {
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	u32 changed;
@@ -227,7 +227,7 @@
 			    sta->reason);
 	spin_unlock_bh(&sta->lock);
 
-	ieee80211_bss_info_change_notify(sdata, changed);
+	return changed;
 }
 
 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
@@ -595,6 +595,10 @@
 	if (!ieee80211_vif_is_mesh(&sta->sdata->vif))
 		return;
 
+	/* no kernel mesh sta timers have been initialized */
+	if (sta->sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE)
+		return;
+
 	if (del_timer_sync(&sta->plink_timer))
 		sta->plink_timer_was_running = true;
 }