From: Felix Fietkau <nbd@openwrt.org>
Date: Thu, 24 Sep 2015 14:10:07 +0200
Subject: [PATCH] mac80211: fix tx sequence number assignment with software
 queue + fast-xmit

When using software queueing, tx sequence number assignment happens at
ieee80211_tx_dequeue time, so the fast-xmit codepath must not do that.

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

--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2766,7 +2766,8 @@ static bool ieee80211_xmit_fast(struct i
 
 	if (hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_QOS_DATA)) {
 		*ieee80211_get_qos_ctl(hdr) = tid;
-		hdr->seq_ctrl = ieee80211_tx_next_seq(sta, tid);
+		if (!sta->sta.txq[0])
+			hdr->seq_ctrl = ieee80211_tx_next_seq(sta, tid);
 	} else {
 		info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
 		hdr->seq_ctrl = cpu_to_le16(sdata->sequence_number);