ath9k: fix mac80211 queue lookup for waking up queues

ath_get_mac80211_qnum() expects the queue 'subtype'
(internal ID for the WMM AC) as argument when looking up
the mac80211 queue, however ath_wake_mac80211_queue provides
txq->axq_qnum instead, which contains the hardware queue
number. Fix this by keeping track of the WMM class ID in
the txq data structure.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -194,6 +194,7 @@ enum ATH_AGGR_STATUS {
 
 #define ATH_TXFIFO_DEPTH 8
 struct ath_txq {
+	int axq_class;
 	u32 axq_qnum;
 	u32 *axq_link;
 	struct list_head axq_q;

drivers/net/wireless/ath/ath9k/xmit.c

@@ -941,6 +941,7 @@ struct ath_txq *ath_txq_setup(struct ath_softc *sc, int qtype, int subtype)
 	if (!ATH_TXQ_SETUP(sc, qnum)) {
 		struct ath_txq *txq = &sc->tx.txq[qnum];
 
+		txq->axq_class = subtype;
 		txq->axq_qnum = qnum;
 		txq->axq_link = NULL;
 		INIT_LIST_HEAD(&txq->axq_q);
@@ -2047,7 +2048,7 @@ static void ath_wake_mac80211_queue(struct ath_softc *sc, struct ath_txq *txq)
 
 	spin_lock_bh(&txq->axq_lock);
 	if (txq->stopped && txq->pending_frames < ATH_MAX_QDEPTH) {
-		qnum = ath_get_mac80211_qnum(txq->axq_qnum, sc);
+		qnum = ath_get_mac80211_qnum(txq->axq_class, sc);
 		if (qnum != -1) {
 			ath_mac80211_start_queue(sc, qnum);
 			txq->stopped = 0;