mac80211: use spin_lock_bh() for tim_lock

There's no need to use _irqsave() as the lock
is never used in interrupt context.

This also fixes a problem in the iwlwifi MVM
driver that calls spin_unlock_bh() within its
set_tim() callback.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/sta_info.c

@@ -571,7 +571,6 @@ void sta_info_recalc_tim(struct sta_info *sta)
 {
 	struct ieee80211_local *local = sta->local;
 	struct ps_data *ps;
-	unsigned long flags;
 	bool indicate_tim = false;
 	u8 ignore_for_tim = sta->sta.uapsd_queues;
 	int ac;
@@ -628,7 +627,7 @@ void sta_info_recalc_tim(struct sta_info *sta)
 	}
 
  done:
-	spin_lock_irqsave(&local->tim_lock, flags);
+	spin_lock_bh(&local->tim_lock);
 
 	if (indicate_tim)
 		__bss_tim_set(ps->tim, id);
@@ -641,7 +640,7 @@ void sta_info_recalc_tim(struct sta_info *sta)
 		local->tim_in_locked_section = false;
 	}
 
-	spin_unlock_irqrestore(&local->tim_lock, flags);
+	spin_unlock_bh(&local->tim_lock);
 }
 
 static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb)

net/mac80211/tx.c

@@ -2364,11 +2364,9 @@ static int ieee80211_beacon_add_tim(struct ieee80211_sub_if_data *sdata,
 	if (local->tim_in_locked_section) {
 		__ieee80211_beacon_add_tim(sdata, ps, skb);
 	} else {
-		unsigned long flags;
-
-		spin_lock_irqsave(&local->tim_lock, flags);
+		spin_lock(&local->tim_lock);
 		__ieee80211_beacon_add_tim(sdata, ps, skb);
-		spin_unlock_irqrestore(&local->tim_lock, flags);
+		spin_unlock(&local->tim_lock);
 	}
 
 	return 0;