+++ /dev/null
-From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@toke.dk>
-Date: Mon, 5 Dec 2016 13:27:37 +0200
-Subject: [PATCH] ath9k: Introduce airtime fairness scheduling between stations
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-This reworks the ath9k driver to schedule transmissions to connected
-stations in a way that enforces airtime fairness between them. It
-accomplishes this by measuring the time spent transmitting to or
-receiving from a station at TX and RX completion, and accounting this to
-a per-station, per-QoS level airtime deficit. Then, an FQ-CoDel based
-deficit scheduler is employed at packet dequeue time, to control which
-station gets the next transmission opportunity.
-
-Airtime fairness can significantly improve the efficiency of the network
-when station rates vary. The following throughput values are from a
-simple three-station test scenario, where two stations operate at the
-highest HT20 rate, and one station at the lowest, and the scheduler is
-employed at the access point:
-
- Before / After
-Fast station 1: 19.17 / 25.09 Mbps
-Fast station 2: 19.83 / 25.21 Mbps
-Slow station: 2.58 / 1.77 Mbps
-Total: 41.58 / 52.07 Mbps
-
-The benefit of airtime fairness goes up the more stations are present.
-In a 30-station test with one station artificially limited to 1 Mbps,
-we have seen aggregate throughput go from 2.14 to 17.76 Mbps.
-
-Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
-Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
----
-
---- 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 *
- #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 CPTCFG_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_sof
- 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
-
- #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;
---- 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 *
- 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_so
- 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;
- }
---- 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;
- }
---- 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
- 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 /* CPTCFG_ATH9K_STATION_STATISTICS */
-
- #endif /* DEBUG_H */
---- 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
- .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 ieee80
-
- 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);
- }
---- 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, s
-
- /* 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);
---- 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(str
- 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:
---- 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(st
- }
- }
-
-+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,
- 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))
---- a/drivers/net/wireless/ath/ath9k/xmit.c
-+++ b/drivers/net/wireless/ath/ath9k/xmit.c
-@@ -125,21 +125,44 @@ void ath_txq_unlock_complete(struct ath_
- 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;
-@@ -154,7 +177,7 @@ void ath9k_wake_tx_queue(struct ieee8021
- 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);
-@@ -684,7 +707,7 @@ static void ath_tx_complete_aggr(struct
-
- 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;
-@@ -712,6 +735,53 @@ static bool bf_is_ampdu_not_probing(stru
- 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)
-@@ -733,6 +803,7 @@ static void ath_tx_process_buffer(struct
-
- 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);
-@@ -1094,8 +1165,8 @@ finish:
- * 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;
-@@ -1493,7 +1564,7 @@ ath_tx_form_burst(struct ath_softc *sc,
- }
-
- 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;
-@@ -1515,7 +1586,6 @@ static bool ath_tx_sched_aggr(struct ath
- 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;
- }
-
-@@ -1639,7 +1709,7 @@ void ath_tx_aggr_wakeup(struct ath_softc
- 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);
-@@ -1956,9 +2026,10 @@ void ath_tx_cleanupq(struct ath_softc *s
- 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;
-@@ -1967,48 +2038,55 @@ void ath_txq_schedule(struct ath_softc *
- 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);
- }
-@@ -2862,6 +2940,9 @@ void ath_tx_node_init(struct ath_softc *
- 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;