mac80211: avoid looking up tid_tx/tid_rx from timers

There's no need to re-lookup the data structures now that
we actually get them immediately with from_timer(), just
avoid that. The struct has to be valid anyway, otherwise
the timer object itself would no longer be valid, and we
can't have a different version of the struct since only a
single session per TID is permitted.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 3 insertions, 14 deletions

diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index d444752dbf40..35e94483fb8c 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -153,27 +153,16 @@ EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
  */
 static void sta_rx_agg_session_timer_expired(struct timer_list *t)
 {
-	struct tid_ampdu_rx *tid_rx_timer =
-		from_timer(tid_rx_timer, t, session_timer);
-	struct sta_info *sta = tid_rx_timer->sta;
-	u8 tid = tid_rx_timer->tid;
-	struct tid_ampdu_rx *tid_rx;
+	struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, session_timer);
+	struct sta_info *sta = tid_rx->sta;
+	u8 tid = tid_rx->tid;
 	unsigned long timeout;
 
-	rcu_read_lock();
-	tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
-	if (!tid_rx) {
-		rcu_read_unlock();
-		return;
-	}
-
 	timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 	if (time_is_after_jiffies(timeout)) {
 		mod_timer(&tid_rx->session_timer, timeout);
-		rcu_read_unlock();
 		return;
 	}
-	rcu_read_unlock();
 
 	ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 	       sta->sta.addr, tid);