mac80211: cancel/restart all timers across suspend/resume

We forgot to cancel all timers in mac80211 when suspending.
In particular we forgot to deal with some things that can
cause hardware reconfiguration -- while it is down.

While at it we go ahead and add a warning in ieee80211_sta_work()
if its run while the suspend->resume cycle is in effect. This
should not happen and if it does it would indicate there is
a bug lurking in either mac80211 or mac80211 drivers.

With this now wpa_supplicant doesn't blink when I go to suspend
and resume where as before there where issues with some timers
running during the suspend->resume cycle. This caused a lot of
incorrect assumptions and would at times bring back the device
in an incoherent, but mostly recoverable, state.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index a8bbdec..cb14253 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -266,6 +266,11 @@
 	 */
 	sta = (struct sta_info *) data;
 
+	if (sta->sdata->local->quiescing) {
+		sta->plink_timer_was_running = true;
+		return;
+	}
+
 	spin_lock_bh(&sta->lock);
 	if (sta->ignore_plink_timer) {
 		sta->ignore_plink_timer = false;
@@ -322,6 +327,22 @@
 	}
 }
 
+#ifdef CONFIG_PM
+void mesh_plink_quiesce(struct sta_info *sta)
+{
+	if (del_timer_sync(&sta->plink_timer))
+		sta->plink_timer_was_running = true;
+}
+
+void mesh_plink_restart(struct sta_info *sta)
+{
+	if (sta->plink_timer_was_running) {
+		add_timer(&sta->plink_timer);
+		sta->plink_timer_was_running = false;
+	}
+}
+#endif
+
 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 {
 	sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);