From: Felix Fietkau <nbd@openwrt.org>
Date: Sat, 15 Nov 2014 22:13:38 +0100
Subject: [PATCH] mac80211: minstrel_ht: add a small optimization to
 minstrel_aggr_check

Check the queue mapping earlier, skb->queue_mapping is more likely than
skb->data to still be in d-cache.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---

--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -690,6 +690,9 @@ minstrel_aggr_check(struct ieee80211_sta
 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 	u16 tid;
 
+	if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
+		return;
+
 	if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
 		return;
 
@@ -700,9 +703,6 @@ minstrel_aggr_check(struct ieee80211_sta
 	if (likely(sta->ampdu_mlme.tid_tx[tid]))
 		return;
 
-	if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
-		return;
-
 	ieee80211_start_tx_ba_session(pubsta, tid, 5000);
 }