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_hwmp.c b/net/mac80211/mesh_hwmp.c
index 60b35ac..003cb47 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -836,8 +836,14 @@
 	mpath = rcu_dereference(mpath);
 	if (!mpath)
 		goto endmpathtimer;
-	spin_lock_bh(&mpath->state_lock);
 	sdata = mpath->sdata;
+
+	if (sdata->local->quiescing) {
+		rcu_read_unlock();
+		return;
+	}
+
+	spin_lock_bh(&mpath->state_lock);
 	if (mpath->flags & MESH_PATH_RESOLVED ||
 			(!(mpath->flags & MESH_PATH_RESOLVING)))
 		mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);