ath9k: fix issues that have been plaguing some powersave clients since the tx queueing rework (#14092)

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

SVN-Revision: 39688

package/kernel/mac80211/patches/300-pending_work.patch

@@ -1,3 +1,20 @@
+commit 0f1cb7be2551b30b02cd54c897e0e29e483cfda5
+Author: Felix Fietkau <nbd@openwrt.org>
+Date:   Sat Feb 22 13:43:29 2014 +0100
+
+    ath9k: fix ps-poll responses under a-mpdu sessions
+    
+    When passing tx frames to the U-APSD queue for powersave poll responses,
+    the ath_atx_tid pointer needs to be passed to ath_tx_setup_buffer for
+    proper sequence number accounting.
+    
+    This fixes high latency and connection stability issues with ath9k
+    running as AP and a few kinds of mobile phones as client, when PS-Poll
+    is heavily used
+    
+    Cc: stable@vger.kernel.org
+    Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
 commit d5d87a37bbd6066b2c3c5d0bd0fe2a6e2ea45cc5
 Author: Felix Fietkau <nbd@openwrt.org>
 Date:   Fri Feb 21 11:39:59 2014 +0100
@@ -3001,6 +3018,24 @@ Date:   Thu Jan 23 20:06:34 2014 +0100
  		buffered = ath_tid_has_buffered(tid);
  
  		tid->sched = false;
+@@ -2184,14 +2186,15 @@ int ath_tx_start(struct ieee80211_hw *hw
+ 		txq->stopped = true;
+ 	}
+ 
++	if (txctl->an)
++		tid = ath_get_skb_tid(sc, txctl->an, skb);
++
+ 	if (info->flags & IEEE80211_TX_CTL_PS_RESPONSE) {
+ 		ath_txq_unlock(sc, txq);
+ 		txq = sc->tx.uapsdq;
+ 		ath_txq_lock(sc, txq);
+ 	} else if (txctl->an &&
+ 		   ieee80211_is_data_present(hdr->frame_control)) {
+-		tid = ath_get_skb_tid(sc, txctl->an, skb);
+-
+ 		WARN_ON(tid->ac->txq != txctl->txq);
+ 
+ 		if (info->flags & IEEE80211_TX_CTL_CLEAR_PS_FILT)
 --- a/drivers/net/wireless/ath/ath9k/init.c
 +++ b/drivers/net/wireless/ath/ath9k/init.c
 @@ -943,6 +943,7 @@ static void ath9k_set_hw_capab(struct at