diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 378d345..79e4b71 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -112,6 +112,8 @@ int ath_descdma_setup(struct ath_softc *sc, struct ath_descdma *dd,
 #define ATH_TXFIFO_DEPTH           8
 #define ATH_TX_ERROR               0x01
 
+#define ATH_AIRTIME_QUANTUM        300 /* usec */
+
 /* Stop tx traffic 1ms before the GO goes away */
 #define ATH_P2P_PS_STOP_TIME       1000
 
@@ -247,6 +249,9 @@ struct ath_atx_tid {
 	bool has_queued;
 };
 
+void __ath_tx_queue_tid(struct ath_softc *sc, struct ath_atx_tid *tid);
+void ath_tx_queue_tid(struct ath_softc *sc, struct ath_atx_tid *tid);
+
 struct ath_node {
 	struct ath_softc *sc;
 	struct ieee80211_sta *sta; /* station struct we're part of */
@@ -258,9 +263,12 @@ struct ath_node {
 
 	bool sleeping;
 	bool no_ps_filter;
+	s64 airtime_deficit[IEEE80211_NUM_ACS];
+	u32 airtime_rx_start;
 
 #ifdef CONFIG_ATH9K_STATION_STATISTICS
 	struct ath_rx_rate_stats rx_rate_stats;
+	struct ath_airtime_stats airtime_stats;
 #endif
 	u8 key_idx[4];
 
@@ -317,10 +325,16 @@ struct ath_rx {
 /* Channel Context */
 /*******************/
 
+struct ath_acq {
+	struct list_head acq_new;
+	struct list_head acq_old;
+	spinlock_t lock;
+};
+
 struct ath_chanctx {
 	struct cfg80211_chan_def chandef;
 	struct list_head vifs;
-	struct list_head acq[IEEE80211_NUM_ACS];
+	struct ath_acq acq[IEEE80211_NUM_ACS];
 	int hw_queue_base;
 
 	/* do not dereference, use for comparison only */
@@ -575,6 +589,8 @@ void ath_txq_schedule_all(struct ath_softc *sc);
 int ath_tx_init(struct ath_softc *sc, int nbufs);
 int ath_txq_update(struct ath_softc *sc, int qnum,
 		   struct ath9k_tx_queue_info *q);
+u32 ath_pkt_duration(struct ath_softc *sc, u8 rix, int pktlen,
+		     int width, int half_gi, bool shortPreamble);
 void ath_update_max_aggr_framelen(struct ath_softc *sc, int queue, int txop);
 void ath_assign_seq(struct ath_common *common, struct sk_buff *skb);
 int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
@@ -963,6 +979,11 @@ void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs);
 
 #define ATH9K_NUM_CHANCTX  2 /* supports 2 operating channels */
 
+#define AIRTIME_USE_TX		BIT(0)
+#define AIRTIME_USE_RX		BIT(1)
+#define AIRTIME_USE_NEW_QUEUES	BIT(2)
+#define AIRTIME_ACTIVE(flags) (!!(flags & (AIRTIME_USE_TX|AIRTIME_USE_RX)))
+
 struct ath_softc {
 	struct ieee80211_hw *hw;
 	struct device *dev;
@@ -1005,6 +1026,8 @@ struct ath_softc {
 	short nbcnvifs;
 	unsigned long ps_usecount;
 
+	u16 airtime_flags; /* AIRTIME_* */
+
 	struct ath_rx rx;
 	struct ath_tx tx;
 	struct ath_beacon beacon;
diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c
index 929dd70..b84539d 100644
--- a/drivers/net/wireless/ath/ath9k/channel.c
+++ b/drivers/net/wireless/ath/ath9k/channel.c
@@ -118,8 +118,11 @@ void ath_chanctx_init(struct ath_softc *sc)
 		INIT_LIST_HEAD(&ctx->vifs);
 		ctx->txpower = ATH_TXPOWER_MAX;
 		ctx->flush_timeout = HZ / 5; /* 200ms */
-		for (j = 0; j < ARRAY_SIZE(ctx->acq); j++)
-			INIT_LIST_HEAD(&ctx->acq[j]);
+		for (j = 0; j < ARRAY_SIZE(ctx->acq); j++) {
+			INIT_LIST_HEAD(&ctx->acq[j].acq_new);
+			INIT_LIST_HEAD(&ctx->acq[j].acq_old);
+			spin_lock_init(&ctx->acq[j].lock);
+		}
 	}
 }
 
@@ -1345,8 +1348,11 @@ void ath9k_offchannel_init(struct ath_softc *sc)
 	ctx->txpower = ATH_TXPOWER_MAX;
 	cfg80211_chandef_create(&ctx->chandef, chan, NL80211_CHAN_HT20);
 
-	for (i = 0; i < ARRAY_SIZE(ctx->acq); i++)
-		INIT_LIST_HEAD(&ctx->acq[i]);
+	for (i = 0; i < ARRAY_SIZE(ctx->acq); i++) {
+		INIT_LIST_HEAD(&ctx->acq[i].acq_new);
+		INIT_LIST_HEAD(&ctx->acq[i].acq_old);
+		spin_lock_init(&ctx->acq[i].lock);
+	}
 
 	sc->offchannel.chan.offchannel = true;
 }
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index 89a94dd..43930c3 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -1399,5 +1399,8 @@ int ath9k_init_debug(struct ath_hw *ah)
 	debugfs_create_file("tpc", S_IRUSR | S_IWUSR,
 			    sc->debug.debugfs_phy, sc, &fops_tpc);
 
+	debugfs_create_u16("airtime_flags", S_IRUSR | S_IWUSR,
+			   sc->debug.debugfs_phy, &sc->airtime_flags);
+
 	return 0;
 }
diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h
index a078cdd..249f814 100644
--- a/drivers/net/wireless/ath/ath9k/debug.h
+++ b/drivers/net/wireless/ath/ath9k/debug.h
@@ -221,6 +221,11 @@ struct ath_rx_rate_stats {
 	} cck_stats[4];
 };
 
+struct ath_airtime_stats {
+	u32 rx_airtime;
+	u32 tx_airtime;
+};
+
 #define ANT_MAIN 0
 #define ANT_ALT  1
 
@@ -314,12 +319,20 @@ ath9k_debug_sync_cause(struct ath_softc *sc, u32 sync_cause)
 void ath_debug_rate_stats(struct ath_softc *sc,
 			  struct ath_rx_status *rs,
 			  struct sk_buff *skb);
+void ath_debug_airtime(struct ath_softc *sc,
+		       struct ath_node *an,
+		       u32 rx, u32 tx);
 #else
 static inline void ath_debug_rate_stats(struct ath_softc *sc,
 					struct ath_rx_status *rs,
 					struct sk_buff *skb)
 {
 }
+static inline void ath_debug_airtime(struct ath_softc *sc,
+			      struct ath_node *an,
+			      u32 rx, u32 tx)
+{
+}
 #endif /* CONFIG_ATH9K_STATION_STATISTICS */
 
 #endif /* DEBUG_H */
diff --git a/drivers/net/wireless/ath/ath9k/debug_sta.c b/drivers/net/wireless/ath/ath9k/debug_sta.c
index 2a3a3c4..524cbf13 100644
--- a/drivers/net/wireless/ath/ath9k/debug_sta.c
+++ b/drivers/net/wireless/ath/ath9k/debug_sta.c
@@ -242,6 +242,59 @@ static const struct file_operations fops_node_recv = {
 	.llseek = default_llseek,
 };
 
+void ath_debug_airtime(struct ath_softc *sc,
+		struct ath_node *an,
+		u32 rx,
+		u32 tx)
+{
+	struct ath_airtime_stats *astats = &an->airtime_stats;
+
+	astats->rx_airtime += rx;
+	astats->tx_airtime += tx;
+}
+
+static ssize_t read_airtime(struct file *file, char __user *user_buf,
+			size_t count, loff_t *ppos)
+{
+	struct ath_node *an = file->private_data;
+	struct ath_airtime_stats *astats;
+	static const char *qname[4] = {
+		"VO", "VI", "BE", "BK"
+	};
+	u32 len = 0, size = 256;
+	char *buf;
+	size_t retval;
+	int i;
+
+	buf = kzalloc(size, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	astats = &an->airtime_stats;
+
+	len += scnprintf(buf + len, size - len, "RX: %u us\n", astats->rx_airtime);
+	len += scnprintf(buf + len, size - len, "TX: %u us\n", astats->tx_airtime);
+	len += scnprintf(buf + len, size - len, "Deficit: ");
+	for (i = 0; i < 4; i++)
+		len += scnprintf(buf+len, size - len, "%s: %lld us ", qname[i], an->airtime_deficit[i]);
+	if (len < size)
+		buf[len++] = '\n';
+
+	retval = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+
+	return retval;
+}
+
+
+static const struct file_operations fops_airtime = {
+	.read = read_airtime,
+	.open = simple_open,
+	.owner = THIS_MODULE,
+	.llseek = default_llseek,
+};
+
+
 void ath9k_sta_add_debugfs(struct ieee80211_hw *hw,
 			   struct ieee80211_vif *vif,
 			   struct ieee80211_sta *sta,
@@ -251,4 +304,5 @@ void ath9k_sta_add_debugfs(struct ieee80211_hw *hw,
 
 	debugfs_create_file("node_aggr", S_IRUGO, dir, an, &fops_node_aggr);
 	debugfs_create_file("node_recv", S_IRUGO, dir, an, &fops_node_recv);
+	debugfs_create_file("airtime", S_IRUGO, dir, an, &fops_airtime);
 }
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index c0c8bf0..5aa665f 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -620,6 +620,8 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc,
 
 	/* Will be cleared in ath9k_start() */
 	set_bit(ATH_OP_INVALID, &common->op_flags);
+	sc->airtime_flags = (AIRTIME_USE_TX | AIRTIME_USE_RX |
+			     AIRTIME_USE_NEW_QUEUES);
 
 	sc->sc_ah = ah;
 	sc->dfs_detector = dfs_pattern_detector_init(common, NL80211_DFS_UNSET);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 59e3bd0..58f06ce 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -70,10 +70,10 @@ static bool ath9k_has_pending_frames(struct ath_softc *sc, struct ath_txq *txq,
 		goto out;
 
 	if (txq->mac80211_qnum >= 0) {
-		struct list_head *list;
+		struct ath_acq *acq;
 
-		list = &sc->cur_chan->acq[txq->mac80211_qnum];
-		if (!list_empty(list))
+		acq = &sc->cur_chan->acq[txq->mac80211_qnum];
+		if (!list_empty(&acq->acq_new) || !list_empty(&acq->acq_old))
 			pending = true;
 	}
 out:
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 6697342..6cc36a8 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -991,6 +991,70 @@ static void ath9k_apply_ampdu_details(struct ath_softc *sc,
 	}
 }
 
+static void ath_rx_count_airtime(struct ath_softc *sc,
+				 struct ath_rx_status *rs,
+				 struct sk_buff *skb)
+{
+	struct ath_node *an;
+	struct ath_acq *acq;
+	struct ath_vif *avp;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath_common *common = ath9k_hw_common(ah);
+	struct ieee80211_sta *sta;
+	struct ieee80211_rx_status *rxs;
+	const struct ieee80211_rate *rate;
+	bool is_sgi, is_40, is_sp;
+	int phy;
+	u16 len = rs->rs_datalen;
+	u32 airtime = 0;
+	u8 tidno, acno;
+
+	if (!ieee80211_is_data(hdr->frame_control))
+		return;
+
+	rcu_read_lock();
+
+	sta = ieee80211_find_sta_by_ifaddr(sc->hw, hdr->addr2, NULL);
+	if (!sta)
+		goto exit;
+	an = (struct ath_node *) sta->drv_priv;
+	avp = (struct ath_vif *) an->vif->drv_priv;
+	tidno = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
+	acno = TID_TO_WME_AC(tidno);
+	acq = &avp->chanctx->acq[acno];
+
+	rxs = IEEE80211_SKB_RXCB(skb);
+
+	is_sgi = !!(rxs->flag & RX_FLAG_SHORT_GI);
+	is_40 = !!(rxs->flag & RX_FLAG_40MHZ);
+	is_sp = !!(rxs->flag & RX_FLAG_SHORTPRE);
+
+	if (!!(rxs->flag & RX_FLAG_HT)) {
+		/* MCS rates */
+
+		airtime += ath_pkt_duration(sc, rxs->rate_idx, len,
+					is_40, is_sgi, is_sp);
+	} else {
+
+		phy = IS_CCK_RATE(rs->rs_rate) ? WLAN_RC_PHY_CCK : WLAN_RC_PHY_OFDM;
+		rate = &common->sbands[rxs->band].bitrates[rxs->rate_idx];
+		airtime += ath9k_hw_computetxtime(ah, phy, rate->bitrate * 100,
+						len, rxs->rate_idx, is_sp);
+	}
+
+ 	if (!!(sc->airtime_flags & AIRTIME_USE_RX)) {
+		spin_lock_bh(&acq->lock);
+		an->airtime_deficit[acno] -= airtime;
+		if (an->airtime_deficit[acno] <= 0)
+			__ath_tx_queue_tid(sc, ATH_AN_2_TID(an, tidno));
+		spin_unlock_bh(&acq->lock);
+	}
+	ath_debug_airtime(sc, an, airtime, 0);
+exit:
+	rcu_read_unlock();
+}
+
 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 {
 	struct ath_rxbuf *bf;
@@ -1137,6 +1201,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 		ath9k_antenna_check(sc, &rs);
 		ath9k_apply_ampdu_details(sc, &rs, rxs);
 		ath_debug_rate_stats(sc, &rs, skb);
+		ath_rx_count_airtime(sc, &rs, skb);
 
 		hdr = (struct ieee80211_hdr *)skb->data;
 		if (ieee80211_is_ack(hdr->frame_control))
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 486afa9..80d4793 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -124,21 +124,44 @@ void ath_txq_unlock_complete(struct ath_softc *sc, struct ath_txq *txq)
 		ath_tx_status(hw, skb);
 }
 
-static void ath_tx_queue_tid(struct ath_softc *sc, struct ath_txq *txq,
-			     struct ath_atx_tid *tid)
+void __ath_tx_queue_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
 {
-	struct list_head *list;
 	struct ath_vif *avp = (struct ath_vif *) tid->an->vif->drv_priv;
 	struct ath_chanctx *ctx = avp->chanctx;
+	struct ath_acq *acq;
+	struct list_head *tid_list;
+	u8 acno = TID_TO_WME_AC(tid->tidno);
 
-	if (!ctx)
+	if (!ctx || !list_empty(&tid->list))
 		return;
 
-	list = &ctx->acq[TID_TO_WME_AC(tid->tidno)];
-	if (list_empty(&tid->list))
-		list_add_tail(&tid->list, list);
+
+	acq = &ctx->acq[acno];
+	if ((sc->airtime_flags & AIRTIME_USE_NEW_QUEUES) &&
+	    tid->an->airtime_deficit[acno] > 0)
+		tid_list = &acq->acq_new;
+	else
+		tid_list = &acq->acq_old;
+
+	list_add_tail(&tid->list, tid_list);
 }
 
+void ath_tx_queue_tid(struct ath_softc *sc, struct ath_atx_tid *tid)
+{
+	struct ath_vif *avp = (struct ath_vif *) tid->an->vif->drv_priv;
+	struct ath_chanctx *ctx = avp->chanctx;
+	struct ath_acq *acq;
+
+	if (!ctx || !list_empty(&tid->list))
+		return;
+
+	acq = &ctx->acq[TID_TO_WME_AC(tid->tidno)];
+	spin_lock_bh(&acq->lock);
+	__ath_tx_queue_tid(sc, tid);
+	spin_unlock_bh(&acq->lock);
+}
+
+
 void ath9k_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *queue)
 {
 	struct ath_softc *sc = hw->priv;
@@ -153,7 +176,7 @@ void ath9k_wake_tx_queue(struct ieee80211_hw *hw, struct ieee80211_txq *queue)
 	ath_txq_lock(sc, txq);
 
 	tid->has_queued = true;
-	ath_tx_queue_tid(sc, txq, tid);
+	ath_tx_queue_tid(sc, tid);
 	ath_txq_schedule(sc, txq);
 
 	ath_txq_unlock(sc, txq);
@@ -660,7 +683,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
 
 		skb_queue_splice_tail(&bf_pending, &tid->retry_q);
 		if (!an->sleeping) {
-			ath_tx_queue_tid(sc, txq, tid);
+			ath_tx_queue_tid(sc, tid);
 
 			if (ts->ts_status & (ATH9K_TXERR_FILT | ATH9K_TXERR_XRETRY))
 				tid->clear_ps_filter = true;
@@ -688,6 +711,53 @@ static bool bf_is_ampdu_not_probing(struct ath_buf *bf)
     return bf_isampdu(bf) && !(info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE);
 }
 
+static void ath_tx_count_airtime(struct ath_softc *sc, struct ath_txq *txq,
+				 struct ath_buf *bf, struct ath_tx_status *ts)
+{
+	struct ath_node *an;
+	struct ath_acq *acq = &sc->cur_chan->acq[txq->mac80211_qnum];
+	struct sk_buff *skb;
+	struct ieee80211_hdr *hdr;
+	struct ieee80211_hw *hw = sc->hw;
+	struct ieee80211_tx_rate rates[4];
+	struct ieee80211_sta *sta;
+	int i;
+	u32 airtime = 0;
+
+	skb = bf->bf_mpdu;
+	if(!skb)
+		return;
+
+	hdr = (struct ieee80211_hdr *)skb->data;
+	memcpy(rates, bf->rates, sizeof(rates));
+
+	rcu_read_lock();
+
+	sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr1, hdr->addr2);
+	if(!sta)
+		goto exit;
+
+
+	an = (struct ath_node *) sta->drv_priv;
+
+	airtime += ts->duration * (ts->ts_longretry + 1);
+
+	for(i=0; i < ts->ts_rateindex; i++)
+		airtime += ath9k_hw_get_duration(sc->sc_ah, bf->bf_desc, i) * rates[i].count;
+
+	if (!!(sc->airtime_flags & AIRTIME_USE_TX)) {
+		spin_lock_bh(&acq->lock);
+		an->airtime_deficit[txq->mac80211_qnum] -= airtime;
+		if (an->airtime_deficit[txq->mac80211_qnum] <= 0)
+			__ath_tx_queue_tid(sc, ath_get_skb_tid(sc, an, skb));
+		spin_unlock_bh(&acq->lock);
+	}
+	ath_debug_airtime(sc, an, 0, airtime);
+
+exit:
+	rcu_read_unlock();
+}
+
 static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
 				  struct ath_tx_status *ts, struct ath_buf *bf,
 				  struct list_head *bf_head)
@@ -709,6 +779,7 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
 
 	ts->duration = ath9k_hw_get_duration(sc->sc_ah, bf->bf_desc,
 					     ts->ts_rateindex);
+	ath_tx_count_airtime(sc, txq, bf, ts);
 
 	hdr = (struct ieee80211_hdr *) bf->bf_mpdu->data;
 	sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr1, hdr->addr2);
@@ -1068,8 +1139,8 @@ ath_tx_form_aggr(struct ath_softc *sc, struct ath_txq *txq,
  * width  - 0 for 20 MHz, 1 for 40 MHz
  * half_gi - to use 4us v/s 3.6 us for symbol time
  */
-static u32 ath_pkt_duration(struct ath_softc *sc, u8 rix, int pktlen,
-			    int width, int half_gi, bool shortPreamble)
+u32 ath_pkt_duration(struct ath_softc *sc, u8 rix, int pktlen,
+		     int width, int half_gi, bool shortPreamble)
 {
 	u32 nbits, nsymbits, duration, nsymbols;
 	int streams;
@@ -1467,7 +1538,7 @@ ath_tx_form_burst(struct ath_softc *sc, struct ath_txq *txq,
 }
 
 static bool ath_tx_sched_aggr(struct ath_softc *sc, struct ath_txq *txq,
-			      struct ath_atx_tid *tid, bool *stop)
+			      struct ath_atx_tid *tid)
 {
 	struct ath_buf *bf;
 	struct ieee80211_tx_info *tx_info;
@@ -1489,7 +1560,6 @@ static bool ath_tx_sched_aggr(struct ath_softc *sc, struct ath_txq *txq,
 	if ((aggr && txq->axq_ampdu_depth >= ATH_AGGR_MIN_QDEPTH) ||
 	    (!aggr && txq->axq_depth >= ATH_NON_AGGR_MIN_QDEPTH)) {
 		__skb_queue_tail(&tid->retry_q, bf->bf_mpdu);
-		*stop = true;
 		return false;
 	}
 
@@ -1613,7 +1683,7 @@ void ath_tx_aggr_wakeup(struct ath_softc *sc, struct ath_node *an)
 		ath_txq_lock(sc, txq);
 		tid->clear_ps_filter = true;
 		if (ath_tid_has_buffered(tid)) {
-			ath_tx_queue_tid(sc, txq, tid);
+			ath_tx_queue_tid(sc, tid);
 			ath_txq_schedule(sc, txq);
 		}
 		ath_txq_unlock_complete(sc, txq);
@@ -1912,9 +1982,10 @@ void ath_tx_cleanupq(struct ath_softc *sc, struct ath_txq *txq)
 void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
 {
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
-	struct ath_atx_tid *tid, *last_tid;
+	struct ath_atx_tid *tid;
 	struct list_head *tid_list;
-	bool sent = false;
+	struct ath_acq *acq;
+	bool active = AIRTIME_ACTIVE(sc->airtime_flags);
 
 	if (txq->mac80211_qnum < 0)
 		return;
@@ -1923,48 +1994,55 @@ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq)
 		return;
 
 	spin_lock_bh(&sc->chan_lock);
-	tid_list = &sc->cur_chan->acq[txq->mac80211_qnum];
-
-	if (list_empty(tid_list)) {
-		spin_unlock_bh(&sc->chan_lock);
-		return;
-	}
-
 	rcu_read_lock();
+	acq = &sc->cur_chan->acq[txq->mac80211_qnum];
 
-	last_tid = list_entry(tid_list->prev, struct ath_atx_tid, list);
-	while (!list_empty(tid_list)) {
-		bool stop = false;
-
-		if (sc->cur_chan->stopped)
-			break;
-
-		tid = list_first_entry(tid_list, struct ath_atx_tid, list);
-		list_del_init(&tid->list);
+	if (sc->cur_chan->stopped)
+		goto out;
 
-		if (ath_tx_sched_aggr(sc, txq, tid, &stop))
-			sent = true;
+begin:
+	tid_list = &acq->acq_new;
+	if (list_empty(tid_list)) {
+		tid_list = &acq->acq_old;
+		if (list_empty(tid_list))
+			goto out;
+	}
+	tid = list_first_entry(tid_list, struct ath_atx_tid, list);
 
-		/*
-		 * add tid to round-robin queue if more frames
-		 * are pending for the tid
-		 */
-		if (ath_tid_has_buffered(tid))
-			ath_tx_queue_tid(sc, txq, tid);
+	if (active && tid->an->airtime_deficit[txq->mac80211_qnum] <= 0) {
+		spin_lock_bh(&acq->lock);
+		tid->an->airtime_deficit[txq->mac80211_qnum] += ATH_AIRTIME_QUANTUM;
+		list_move_tail(&tid->list, &acq->acq_old);
+		spin_unlock_bh(&acq->lock);
+		goto begin;
+	}
 
-		if (stop)
-			break;
+	if (!ath_tid_has_buffered(tid)) {
+		spin_lock_bh(&acq->lock);
+		if ((tid_list == &acq->acq_new) && !list_empty(&acq->acq_old))
+			list_move_tail(&tid->list, &acq->acq_old);
+		else {
+			list_del_init(&tid->list);
+		}
+		spin_unlock_bh(&acq->lock);
+		goto begin;
+	}
 
-		if (tid == last_tid) {
-			if (!sent)
-				break;
 
-			sent = false;
-			last_tid = list_entry(tid_list->prev,
-					      struct ath_atx_tid, list);
+	/*
+	 * If we succeed in scheduling something, immediately restart to make
+	 * sure we keep the HW busy.
+	 */
+	if(ath_tx_sched_aggr(sc, txq, tid)) {
+		if (!active) {
+			spin_lock_bh(&acq->lock);
+			list_move_tail(&tid->list, &acq->acq_old);
+			spin_unlock_bh(&acq->lock);
 		}
+		goto begin;
 	}
 
+out:
 	rcu_read_unlock();
 	spin_unlock_bh(&sc->chan_lock);
 }
@@ -2818,6 +2896,9 @@ void ath_tx_node_init(struct ath_softc *sc, struct ath_node *an)
 	struct ath_atx_tid *tid;
 	int tidno, acno;
 
+	for (acno = 0; acno < IEEE80211_NUM_ACS; acno++)
+		an->airtime_deficit[acno] = ATH_AIRTIME_QUANTUM;
+
 	for (tidno = 0; tidno < IEEE80211_NUM_TIDS; tidno++) {
 		tid = ath_node_to_tid(an, tidno);
 		tid->an        = an;
