.ht_cap         = AR9170_HT_CAP,
 };
 
-#ifdef AR9170_QUEUE_DEBUG
-/*
- * In case some wants works with AR9170's crazy tx_status queueing techniques.
- * He might need this rather useful probing function.
- *
- * NOTE: caller must hold the queue's spinlock!
- */
+static void ar9170_tx(struct ar9170 *ar);
 
+#ifdef AR9170_QUEUE_DEBUG
 static void ar9170_print_txheader(struct ar9170 *ar, struct sk_buff *skb)
 {
        struct ar9170_tx_control *txc = (void *) skb->data;
-       struct ieee80211_hdr *hdr = (void *)txc->frame_data;
+       struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
+       struct ar9170_tx_info *arinfo = (void *) txinfo->rate_driver_data;
+       struct ieee80211_hdr *hdr = (void *) txc->frame_data;
 
-       printk(KERN_DEBUG "%s: => FRAME [skb:%p, queue:%d, DA:[%pM] "
-                         "mac_control:%04x, phy_control:%08x]\n",
+       printk(KERN_DEBUG "%s: => FRAME [skb:%p, q:%d, DA:[%pM] flags:%x "
+                         "mac_ctrl:%04x, phy_ctrl:%08x, timeout:[%d ms]]\n",
               wiphy_name(ar->hw->wiphy), skb, skb_get_queue_mapping(skb),
-              ieee80211_get_DA(hdr), le16_to_cpu(txc->mac_control),
-              le32_to_cpu(txc->phy_control));
+              ieee80211_get_DA(hdr), arinfo->flags,
+              le16_to_cpu(txc->mac_control), le32_to_cpu(txc->phy_control),
+              jiffies_to_msecs(arinfo->timeout - jiffies));
 }
 
-static void ar9170_dump_station_tx_status_queue(struct ar9170 *ar,
-                                               struct sk_buff_head *queue)
+static void __ar9170_dump_txqueue(struct ar9170 *ar,
+                               struct sk_buff_head *queue)
 {
        struct sk_buff *skb;
        int i = 0;
 
        printk(KERN_DEBUG "---[ cut here ]---\n");
-       printk(KERN_DEBUG "%s: %d entries in tx_status queue.\n",
+       printk(KERN_DEBUG "%s: %d entries in queue.\n",
               wiphy_name(ar->hw->wiphy), skb_queue_len(queue));
 
        skb_queue_walk(queue, skb) {
-               struct ar9170_tx_control *txc = (void *) skb->data;
-               struct ieee80211_hdr *hdr = (void *)txc->frame_data;
-
-               printk(KERN_DEBUG "index:%d => \n", i);
+               printk(KERN_DEBUG "index:%d => \n", i++);
                ar9170_print_txheader(ar, skb);
        }
+       if (i != skb_queue_len(queue))
+               printk(KERN_DEBUG "WARNING: queue frame counter "
+                      "mismatch %d != %d\n", skb_queue_len(queue), i);
        printk(KERN_DEBUG "---[ end ]---\n");
 }
-#endif /* AR9170_QUEUE_DEBUG */
 
-void ar9170_handle_tx_status(struct ar9170 *ar, struct sk_buff *skb,
-                            bool valid_status, u16 tx_status)
+static void ar9170_dump_txqueue(struct ar9170 *ar,
+                               struct sk_buff_head *queue)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&queue->lock, flags);
+       __ar9170_dump_txqueue(ar, queue);
+       spin_unlock_irqrestore(&queue->lock, flags);
+}
+
+static void __ar9170_dump_txstats(struct ar9170 *ar)
+{
+       int i;
+
+       printk(KERN_DEBUG "%s: QoS queue stats\n",
+              wiphy_name(ar->hw->wiphy));
+
+       for (i = 0; i < __AR9170_NUM_TXQ; i++)
+               printk(KERN_DEBUG "%s: queue:%d limit:%d len:%d waitack:%d\n",
+                      wiphy_name(ar->hw->wiphy), i, ar->tx_stats[i].limit,
+                      ar->tx_stats[i].len, skb_queue_len(&ar->tx_status[i]));
+}
+
+static void ar9170_dump_txstats(struct ar9170 *ar)
 {
-       struct ieee80211_tx_info *txinfo;
-       unsigned int retries = 0, queue = skb_get_queue_mapping(skb);
        unsigned long flags;
 
        spin_lock_irqsave(&ar->tx_stats_lock, flags);
-       ar->tx_stats[queue].len--;
-       if (ieee80211_queue_stopped(ar->hw, queue))
-               ieee80211_wake_queue(ar->hw, queue);
+       __ar9170_dump_txstats(ar);
        spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
+}
+#endif /* AR9170_QUEUE_DEBUG */
+
+/* caller must guarantee exclusive access for _bin_ queue. */
+static void ar9170_recycle_expired(struct ar9170 *ar,
+                                  struct sk_buff_head *queue,
+                                  struct sk_buff_head *bin)
+{
+       struct sk_buff *skb, *old = NULL;
+       unsigned long flags;
+
+       spin_lock_irqsave(&queue->lock, flags);
+       while ((skb = skb_peek(queue))) {
+               struct ieee80211_tx_info *txinfo;
+               struct ar9170_tx_info *arinfo;
+
+               txinfo = IEEE80211_SKB_CB(skb);
+               arinfo = (void *) txinfo->rate_driver_data;
+
+               if (time_is_before_jiffies(arinfo->timeout)) {
+#ifdef AR9170_QUEUE_DEBUG
+                       printk(KERN_DEBUG "%s: [%ld > %ld] frame expired => "
+                              "recycle \n", wiphy_name(ar->hw->wiphy),
+                              jiffies, arinfo->timeout);
+                       ar9170_print_txheader(ar, skb);
+#endif /* AR9170_QUEUE_DEBUG */
+                       __skb_unlink(skb, queue);
+                       __skb_queue_tail(bin, skb);
+               } else {
+                       break;
+               }
+
+               if (unlikely(old == skb)) {
+                       /* bail out - queue is shot. */
+
+                       WARN_ON(1);
+                       break;
+               }
+               old = skb;
+       }
+       spin_unlock_irqrestore(&queue->lock, flags);
+}
+
+static void ar9170_tx_status(struct ar9170 *ar, struct sk_buff *skb,
+                                   u16 tx_status)
+{
+       struct ieee80211_tx_info *txinfo;
+       unsigned int retries = 0;
 
        txinfo = IEEE80211_SKB_CB(skb);
        ieee80211_tx_info_clear_status(txinfo);
                break;
        }
 
-       if (valid_status)
-               txinfo->status.rates[0].count = retries + 1;
-
+       txinfo->status.rates[0].count = retries + 1;
        skb_pull(skb, sizeof(struct ar9170_tx_control));
        ieee80211_tx_status_irqsafe(ar->hw, skb);
 }
 
-static struct sk_buff *ar9170_find_skb_in_queue(struct ar9170 *ar,
-                                               const u8 *mac,
-                                               const u32 queue,
-                                               struct sk_buff_head *q)
+void ar9170_tx_callback(struct ar9170 *ar, struct sk_buff *skb)
 {
+       struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+       struct ar9170_tx_info *arinfo = (void *) info->rate_driver_data;
+       unsigned int queue = skb_get_queue_mapping(skb);
        unsigned long flags;
-       struct sk_buff *skb;
 
-       spin_lock_irqsave(&q->lock, flags);
-       skb_queue_walk(q, skb) {
-               struct ar9170_tx_control *txc = (void *) skb->data;
-               struct ieee80211_hdr *hdr = (void *) txc->frame_data;
-               u32 txc_queue = (le32_to_cpu(txc->phy_control) &
-                               AR9170_TX_PHY_QOS_MASK) >>
-                               AR9170_TX_PHY_QOS_SHIFT;
+       spin_lock_irqsave(&ar->tx_stats_lock, flags);
+       ar->tx_stats[queue].len--;
 
-               if  ((queue != txc_queue) ||
-                    (compare_ether_addr(ieee80211_get_DA(hdr), mac)))
-                       continue;
+       if (skb_queue_empty(&ar->tx_pending[queue])) {
+#ifdef AR9170_QUEUE_STOP_DEBUG
+               printk(KERN_DEBUG "%s: wake queue %d\n",
+                      wiphy_name(ar->hw->wiphy), queue);
+               __ar9170_dump_txstats(ar);
+#endif /* AR9170_QUEUE_STOP_DEBUG */
+               ieee80211_wake_queue(ar->hw, queue);
+       }
+       spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
 
-               __skb_unlink(skb, q);
-               spin_unlock_irqrestore(&q->lock, flags);
-               return skb;
+       if (arinfo->flags & AR9170_TX_FLAG_BLOCK_ACK) {
+               dev_kfree_skb_any(skb);
+       } else if (arinfo->flags & AR9170_TX_FLAG_WAIT_FOR_ACK) {
+               arinfo->timeout = jiffies +
+                                 msecs_to_jiffies(AR9170_TX_TIMEOUT);
+
+               skb_queue_tail(&ar->tx_status[queue], skb);
+       } else if (arinfo->flags & AR9170_TX_FLAG_NO_ACK) {
+               ar9170_tx_status(ar, skb, AR9170_TX_STATUS_FAILED);
+       } else {
+#ifdef AR9170_QUEUE_DEBUG
+               printk(KERN_DEBUG "%s: unsupported frame flags!\n",
+                      wiphy_name(ar->hw->wiphy));
+               ar9170_print_txheader(ar, skb);
+#endif /* AR9170_QUEUE_DEBUG */
+               dev_kfree_skb_any(skb);
+       }
+
+       if (!ar->tx_stats[queue].len &&
+           !skb_queue_empty(&ar->tx_pending[queue])) {
+               ar9170_tx(ar);
        }
-       spin_unlock_irqrestore(&q->lock, flags);
-       return NULL;
 }
 
-static struct sk_buff *ar9170_find_queued_skb(struct ar9170 *ar, const u8 *mac,
-                                             const u32 queue)
+static struct sk_buff *ar9170_get_queued_skb(struct ar9170 *ar,
+                                            const u8 *mac,
+                                            struct sk_buff_head *queue,
+                                            const u32 rate)
 {
-       struct ieee80211_sta *sta;
+       unsigned long flags;
        struct sk_buff *skb;
 
        /*
         * the firmware provided (-> destination MAC, and phy_control) -
         * and hope that we picked the right one...
         */
-       rcu_read_lock();
-       sta = ieee80211_find_sta(ar->hw, mac);
-
-       if (likely(sta)) {
-               struct ar9170_sta_info *sta_priv = (void *) sta->drv_priv;
-               skb = skb_dequeue(&sta_priv->tx_status[queue]);
-               rcu_read_unlock();
-               if (likely(skb))
-                       return skb;
-       } else
-               rcu_read_unlock();
-
-       /* scan the waste queue for candidates */
-       skb = ar9170_find_skb_in_queue(ar, mac, queue,
-                                      &ar->global_tx_status_waste);
-       if (!skb) {
-               /* so it still _must_ be in the global list. */
-               skb = ar9170_find_skb_in_queue(ar, mac, queue,
-                                              &ar->global_tx_status);
-       }
 
+       spin_lock_irqsave(&queue->lock, flags);
+       skb_queue_walk(queue, skb) {
+               struct ar9170_tx_control *txc = (void *) skb->data;
+               struct ieee80211_hdr *hdr = (void *) txc->frame_data;
+               u32 r;
+
+               if (mac && compare_ether_addr(ieee80211_get_DA(hdr), mac)) {
 #ifdef AR9170_QUEUE_DEBUG
-       if (unlikely((!skb) && net_ratelimit())) {
-               printk(KERN_ERR "%s: ESS:[%pM] does not have any "
-                               "outstanding frames in this queue (%d).\n",
-                               wiphy_name(ar->hw->wiphy), mac, queue);
+                       printk(KERN_DEBUG "%s: skip frame => DA %pM != %pM\n",
+                              wiphy_name(ar->hw->wiphy), mac,
+                              ieee80211_get_DA(hdr));
+                       ar9170_print_txheader(ar, skb);
+#endif /* AR9170_QUEUE_DEBUG */
+                       continue;
+               }
+
+               r = (le32_to_cpu(txc->phy_control) & AR9170_TX_PHY_MCS_MASK) >>
+                   AR9170_TX_PHY_MCS_SHIFT;
+
+               if ((rate != AR9170_TX_INVALID_RATE) && (r != rate)) {
+#ifdef AR9170_QUEUE_DEBUG
+                       printk(KERN_DEBUG "%s: skip frame => rate %d != %d\n",
+                              wiphy_name(ar->hw->wiphy), rate, r);
+                       ar9170_print_txheader(ar, skb);
+#endif /* AR9170_QUEUE_DEBUG */
+                       continue;
+               }
+
+               __skb_unlink(skb, queue);
+               spin_unlock_irqrestore(&queue->lock, flags);
+               return skb;
        }
+
+#ifdef AR9170_QUEUE_DEBUG
+       printk(KERN_ERR "%s: ESS:[%pM] does not have any "
+                       "outstanding frames in queue.\n",
+                       wiphy_name(ar->hw->wiphy), mac);
+       __ar9170_dump_txqueue(ar, queue);
 #endif /* AR9170_QUEUE_DEBUG */
-       return skb;
+       spin_unlock_irqrestore(&queue->lock, flags);
+
+       return NULL;
 }
 
 /*
- * This worker tries to keep the global tx_status queue empty.
- * So we can guarantee that incoming tx_status reports for
- * unregistered stations are always synced with the actual
- * frame - which we think - belongs to.
+ * This worker tries to keeps an maintain tx_status queues.
+ * So we can guarantee that incoming tx_status reports are
+ * actually for a pending frame.
  */
 
-static void ar9170_tx_status_janitor(struct work_struct *work)
+static void ar9170_tx_janitor(struct work_struct *work)
 {
        struct ar9170 *ar = container_of(work, struct ar9170,
-                                        tx_status_janitor.work);
-       struct sk_buff *skb;
+                                        tx_janitor.work);
+       struct sk_buff_head waste;
+       unsigned int i;
+       bool resched = false;
 
        if (unlikely(!IS_STARTED(ar)))
                return ;
 
-       /* recycle the garbage back to mac80211... one by one. */
-       while ((skb = skb_dequeue(&ar->global_tx_status_waste))) {
+       skb_queue_head_init(&waste);
+
+       for (i = 0; i < __AR9170_NUM_TXQ; i++) {
 #ifdef AR9170_QUEUE_DEBUG
-               printk(KERN_DEBUG "%s: dispose queued frame =>\n",
-                      wiphy_name(ar->hw->wiphy));
-               ar9170_print_txheader(ar, skb);
+               printk(KERN_DEBUG "%s: garbage collector scans queue:%d\n",
+                      wiphy_name(ar->hw->wiphy), i);
+               ar9170_dump_txqueue(ar, &ar->tx_pending[i]);
+               ar9170_dump_txqueue(ar, &ar->tx_status[i]);
 #endif /* AR9170_QUEUE_DEBUG */
-               ar9170_handle_tx_status(ar, skb, false,
-                                       AR9170_TX_STATUS_FAILED);
-       }
 
-       while ((skb = skb_dequeue(&ar->global_tx_status))) {
-#ifdef AR9170_QUEUE_DEBUG
-               printk(KERN_DEBUG "%s: moving frame into waste queue =>\n",
-                      wiphy_name(ar->hw->wiphy));
+               ar9170_recycle_expired(ar, &ar->tx_status[i], &waste);
+               ar9170_recycle_expired(ar, &ar->tx_pending[i], &waste);
+               skb_queue_purge(&waste);
 
-               ar9170_print_txheader(ar, skb);
-#endif /* AR9170_QUEUE_DEBUG */
-               skb_queue_tail(&ar->global_tx_status_waste, skb);
+               if (!skb_queue_empty(&ar->tx_status[i]) ||
+                   !skb_queue_empty(&ar->tx_pending[i]))
+                       resched = true;
        }
 
-       /* recall the janitor in 100ms - if there's garbage in the can. */
-       if (skb_queue_len(&ar->global_tx_status_waste) > 0)
-               queue_delayed_work(ar->hw->workqueue, &ar->tx_status_janitor,
-                                  msecs_to_jiffies(100));
+       if (resched)
+               queue_delayed_work(ar->hw->workqueue,
+                                  &ar->tx_janitor,
+                                  msecs_to_jiffies(AR9170_JANITOR_DELAY));
 }
 
 void ar9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len)
                 */
 
                struct sk_buff *skb;
-               u32 queue = (le32_to_cpu(cmd->tx_status.rate) &
-                           AR9170_TX_PHY_QOS_MASK) >> AR9170_TX_PHY_QOS_SHIFT;
+               u32 phy = le32_to_cpu(cmd->tx_status.rate);
+               u32 q = (phy & AR9170_TX_PHY_QOS_MASK) >>
+                       AR9170_TX_PHY_QOS_SHIFT;
+#ifdef AR9170_QUEUE_DEBUG
+               printk(KERN_DEBUG "%s: recv tx_status for %pM, p:%08x, q:%d\n",
+                      wiphy_name(ar->hw->wiphy), cmd->tx_status.dst, phy, q);
+#endif /* AR9170_QUEUE_DEBUG */
 
-               skb = ar9170_find_queued_skb(ar, cmd->tx_status.dst, queue);
+               skb = ar9170_get_queued_skb(ar, cmd->tx_status.dst,
+                                           &ar->tx_status[q],
+                                           AR9170_TX_INVALID_RATE);
                if (unlikely(!skb))
                        return ;
 
-               ar9170_handle_tx_status(ar, skb, true,
-                                       le16_to_cpu(cmd->tx_status.status));
+               ar9170_tx_status(ar, skb, le16_to_cpu(cmd->tx_status.status));
                break;
                }
 
        ar->rx_mpdu.has_plcp = false;
 }
 
-static int ar9170_nag_limiter(struct ar9170 *ar)
+int ar9170_nag_limiter(struct ar9170 *ar)
 {
        bool print_message;
 
 
        /* reinitialize queues statistics */
        memset(&ar->tx_stats, 0, sizeof(ar->tx_stats));
-       for (i = 0; i < ARRAY_SIZE(ar->tx_stats); i++)
-               ar->tx_stats[i].limit = 8;
+       for (i = 0; i < __AR9170_NUM_TXQ; i++)
+               ar->tx_stats[i].limit = AR9170_TXQ_DEPTH;
 
        /* reset QoS defaults */
        AR9170_FILL_QUEUE(ar->edcf[0], 3, 15, 1023,  0); /* BEST EFFORT*/
 static void ar9170_op_stop(struct ieee80211_hw *hw)
 {
        struct ar9170 *ar = hw->priv;
+       unsigned int i;
 
        if (IS_STARTED(ar))
                ar->state = AR9170_IDLE;
 
        flush_workqueue(ar->hw->workqueue);
 
-       cancel_delayed_work_sync(&ar->tx_status_janitor);
+       cancel_delayed_work_sync(&ar->tx_janitor);
        cancel_work_sync(&ar->filter_config_work);
        cancel_work_sync(&ar->beacon_work);
        mutex_lock(&ar->mutex);
-       skb_queue_purge(&ar->global_tx_status_waste);
-       skb_queue_purge(&ar->global_tx_status);
 
        if (IS_ACCEPTING_CMD(ar)) {
                ar9170_set_leds_state(ar, 0);
                ar->stop(ar);
        }
 
+       for (i = 0; i < __AR9170_NUM_TXQ; i++) {
+               skb_queue_purge(&ar->tx_pending[i]);
+               skb_queue_purge(&ar->tx_status[i]);
+       }
        mutex_unlock(&ar->mutex);
 }
 
-int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
+static int ar9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
 {
-       struct ar9170 *ar = hw->priv;
        struct ieee80211_hdr *hdr;
        struct ar9170_tx_control *txc;
        struct ieee80211_tx_info *info;
-       struct ieee80211_rate *rate = NULL;
        struct ieee80211_tx_rate *txrate;
+       struct ar9170_tx_info *arinfo;
        unsigned int queue = skb_get_queue_mapping(skb);
-       unsigned long flags = 0;
-       struct ar9170_sta_info *sta_info = NULL;
-       u32 power, chains;
        u16 keytype = 0;
        u16 len, icv = 0;
-       int err;
-       bool tx_status;
 
-       if (unlikely(!IS_STARTED(ar)))
-               goto err_free;
+       BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
 
        hdr = (void *)skb->data;
        info = IEEE80211_SKB_CB(skb);
        len = skb->len;
 
-       spin_lock_irqsave(&ar->tx_stats_lock, flags);
-       if (ar->tx_stats[queue].limit < ar->tx_stats[queue].len) {
-               spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
-               return NETDEV_TX_OK;
-       }
-
-       ar->tx_stats[queue].len++;
-       ar->tx_stats[queue].count++;
-       if (ar->tx_stats[queue].limit == ar->tx_stats[queue].len)
-               ieee80211_stop_queue(hw, queue);
-
-       spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
-
        txc = (void *)skb_push(skb, sizeof(*txc));
 
-       tx_status = (((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) != 0) ||
-                   ((info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS) != 0));
-
        if (info->control.hw_key) {
                icv = info->control.hw_key->icv_len;
 
                        break;
                default:
                        WARN_ON(1);
-                       goto err_dequeue;
+                       goto err_out;
                }
        }
 
        if (info->flags & IEEE80211_TX_CTL_NO_ACK)
                txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_NO_ACK);
 
-       if (info->flags & IEEE80211_TX_CTL_AMPDU)
-               txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_AGGR);
-
        txrate = &info->control.rates[0];
-
        if (txrate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
                txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
        else if (txrate->flags & IEEE80211_TX_RC_USE_RTS_CTS)
                txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);
 
+       arinfo = (void *)info->rate_driver_data;
+       arinfo->timeout = jiffies + msecs_to_jiffies(AR9170_QUEUE_TIMEOUT);
+
+       if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
+            (is_valid_ether_addr(ieee80211_get_DA(hdr)))) {
+               if (info->flags & IEEE80211_TX_CTL_AMPDU) {
+                       if (unlikely(!info->control.sta))
+                               goto err_out;
+
+                       txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_AGGR);
+                       arinfo->flags = AR9170_TX_FLAG_BLOCK_ACK;
+                       goto out;
+               }
+
+               txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_RATE_PROBE);
+               /*
+                * WARNING:
+                * Putting the QoS queue bits into an unexplored territory is
+                * certainly not elegant.
+                *
+                * In my defense: This idea provides a reasonable way to
+                * smuggle valuable information to the tx_status callback.
+                * Also, the idea behind this bit-abuse came straight from
+                * the original driver code.
+                */
+
+               txc->phy_control |=
+                       cpu_to_le32(queue << AR9170_TX_PHY_QOS_SHIFT);
+               arinfo->flags = AR9170_TX_FLAG_WAIT_FOR_ACK;
+       } else {
+               arinfo->flags = AR9170_TX_FLAG_NO_ACK;
+       }
+
+out:
+       return 0;
+
+err_out:
+       skb_pull(skb, sizeof(*txc));
+       return -EINVAL;
+}
+
+static void ar9170_tx_prepare_phy(struct ar9170 *ar, struct sk_buff *skb)
+{
+       struct ar9170_tx_control *txc;
+       struct ieee80211_tx_info *info;
+       struct ieee80211_rate *rate = NULL;
+       struct ieee80211_tx_rate *txrate;
+       u32 power, chains;
+
+       txc = (void *) skb->data;
+       info = IEEE80211_SKB_CB(skb);
+       txrate = &info->control.rates[0];
+
        if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_GREENFIELD);
 
                u32 r = txrate->idx;
                u8 *txpower;
 
+               /* heavy clip control */
+               txc->phy_control |= cpu_to_le32((r & 0x7) << 7);
+
                r <<= AR9170_TX_PHY_MCS_SHIFT;
-               if (WARN_ON(r & ~AR9170_TX_PHY_MCS_MASK))
-                       goto err_dequeue;
+               BUG_ON(r & ~AR9170_TX_PHY_MCS_MASK);
+
                txc->phy_control |= cpu_to_le32(r & AR9170_TX_PHY_MCS_MASK);
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_MOD_HT);
 
                        chains = AR9170_TX_PHY_TXCHAIN_1;
        }
        txc->phy_control |= cpu_to_le32(chains << AR9170_TX_PHY_TXCHAIN_SHIFT);
+}
 
-       if (tx_status) {
-               txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_RATE_PROBE);
-               /*
-                * WARNING:
-                * Putting the QoS queue bits into an unexplored territory is
-                * certainly not elegant.
-                *
-                * In my defense: This idea provides a reasonable way to
-                * smuggle valuable information to the tx_status callback.
-                * Also, the idea behind this bit-abuse came straight from
-                * the original driver code.
-                */
+static void ar9170_tx(struct ar9170 *ar)
+{
+       struct sk_buff *skb;
+       unsigned long flags;
+       struct ieee80211_tx_info *info;
+       struct ar9170_tx_info *arinfo;
+       unsigned int i, frames, frames_failed, remaining_space;
+       int err;
+       bool schedule_garbagecollector = false;
 
-               txc->phy_control |=
-                       cpu_to_le32(queue << AR9170_TX_PHY_QOS_SHIFT);
+       BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
 
-               if (info->control.sta) {
-                       sta_info = (void *) info->control.sta->drv_priv;
-                       skb_queue_tail(&sta_info->tx_status[queue], skb);
-               } else {
-                       skb_queue_tail(&ar->global_tx_status, skb);
+       if (unlikely(!IS_STARTED(ar)))
+               return ;
+
+       remaining_space = AR9170_TX_MAX_PENDING;
+
+       for (i = 0; i < __AR9170_NUM_TXQ; i++) {
+               spin_lock_irqsave(&ar->tx_stats_lock, flags);
+               if (ar->tx_stats[i].len >= ar->tx_stats[i].limit) {
+#ifdef AR9170_QUEUE_DEBUG
+                       printk(KERN_DEBUG "%s: queue %d full\n",
+                              wiphy_name(ar->hw->wiphy), i);
+
+                       __ar9170_dump_txstats(ar);
+                       printk(KERN_DEBUG "stuck frames: ===> \n");
+                       ar9170_dump_txqueue(ar, &ar->tx_pending[i]);
+                       ar9170_dump_txqueue(ar, &ar->tx_status[i]);
+#endif /* AR9170_QUEUE_DEBUG */
+                       ieee80211_stop_queue(ar->hw, i);
+                       spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
+                       continue;
+               }
 
-                       queue_delayed_work(ar->hw->workqueue,
-                                          &ar->tx_status_janitor,
-                                          msecs_to_jiffies(100));
+               frames = min(ar->tx_stats[i].limit - ar->tx_stats[i].len,
+                            skb_queue_len(&ar->tx_pending[i]));
+
+               if (remaining_space < frames) {
+#ifdef AR9170_QUEUE_DEBUG
+                       printk(KERN_DEBUG "%s: tx quota reached queue:%d, "
+                              "remaining slots:%d, needed:%d\n",
+                              wiphy_name(ar->hw->wiphy), i, remaining_space,
+                              frames);
+
+                       ar9170_dump_txstats(ar);
+#endif /* AR9170_QUEUE_DEBUG */
+                       frames = remaining_space;
+               }
+
+               ar->tx_stats[i].len += frames;
+               ar->tx_stats[i].count += frames;
+               spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
+
+               if (!frames)
+                       continue;
+
+               frames_failed = 0;
+               while (frames) {
+                       skb = skb_dequeue(&ar->tx_pending[i]);
+                       if (unlikely(!skb)) {
+                               frames_failed += frames;
+                               frames = 0;
+                               break;
+                       }
+
+                       info = IEEE80211_SKB_CB(skb);
+                       arinfo = (void *) info->rate_driver_data;
+
+                       /* TODO: cancel stuck frames */
+                       arinfo->timeout = jiffies +
+                                         msecs_to_jiffies(AR9170_TX_TIMEOUT);
+
+#ifdef AR9170_QUEUE_DEBUG
+                       printk(KERN_DEBUG "%s: send frame q:%d =>\n",
+                              wiphy_name(ar->hw->wiphy), i);
+                       ar9170_print_txheader(ar, skb);
+#endif /* AR9170_QUEUE_DEBUG */
+
+                       err = ar->tx(ar, skb);
+                       if (unlikely(err)) {
+                               frames_failed++;
+                               dev_kfree_skb_any(skb);
+                       } else {
+                               remaining_space--;
+                               schedule_garbagecollector = true;
+                       }
+
+                       frames--;
+               }
+
+#ifdef AR9170_QUEUE_DEBUG
+               printk(KERN_DEBUG "%s: ar9170_tx report for queue %d\n",
+                      wiphy_name(ar->hw->wiphy), i);
+
+               printk(KERN_DEBUG "%s: unprocessed pending frames left:\n",
+                      wiphy_name(ar->hw->wiphy));
+               ar9170_dump_txqueue(ar, &ar->tx_pending[i]);
+#endif /* AR9170_QUEUE_DEBUG */
+
+               if (unlikely(frames_failed)) {
+#ifdef AR9170_QUEUE_DEBUG
+                       printk(KERN_DEBUG "%s: frames failed =>\n",
+                              wiphy_name(ar->hw->wiphy), frames_failed);
+#endif /* AR9170_QUEUE_DEBUG */
+
+                       spin_lock_irqsave(&ar->tx_stats_lock, flags);
+                       ar->tx_stats[i].len -= frames_failed;
+                       ar->tx_stats[i].count -= frames_failed;
+                       ieee80211_wake_queue(ar->hw, i);
+                       spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
                }
        }
 
-       err = ar->tx(ar, skb, tx_status, 0);
-       if (unlikely(tx_status && err)) {
-               if (info->control.sta)
-                       skb_unlink(skb, &sta_info->tx_status[queue]);
-               else
-                       skb_unlink(skb, &ar->global_tx_status);
+       if (schedule_garbagecollector)
+               queue_delayed_work(ar->hw->workqueue,
+                                  &ar->tx_janitor,
+                                  msecs_to_jiffies(AR9170_JANITOR_DELAY));
+}
+
+int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
+{
+       struct ar9170 *ar = hw->priv;
+       struct ieee80211_tx_info *info;
+
+       if (unlikely(!IS_STARTED(ar)))
+               goto err_free;
+
+       if (unlikely(ar9170_tx_prepare(ar, skb)))
+               goto err_free;
+
+       info = IEEE80211_SKB_CB(skb);
+       if (info->flags & IEEE80211_TX_CTL_AMPDU) {
+               /* drop frame, we do not allow TX A-MPDU aggregation yet. */
+               goto err_free;
+       } else {
+               unsigned int queue = skb_get_queue_mapping(skb);
+
+               ar9170_tx_prepare_phy(ar, skb);
+               skb_queue_tail(&ar->tx_pending[queue], skb);
        }
 
+       ar9170_tx(ar);
        return NETDEV_TX_OK;
 
-err_dequeue:
-       spin_lock_irqsave(&ar->tx_stats_lock, flags);
-       ar->tx_stats[queue].len--;
-       ar->tx_stats[queue].count--;
-       spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
-
 err_free:
-       dev_kfree_skb(skb);
+       dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
 }
 
                              enum sta_notify_cmd cmd,
                              struct ieee80211_sta *sta)
 {
-       struct ar9170 *ar = hw->priv;
-       struct ar9170_sta_info *info = (void *) sta->drv_priv;
-       struct sk_buff *skb;
-       unsigned int i;
-
-       switch (cmd) {
-       case STA_NOTIFY_ADD:
-               for (i = 0; i < ar->hw->queues; i++)
-                       skb_queue_head_init(&info->tx_status[i]);
-               break;
-
-       case STA_NOTIFY_REMOVE:
-
-               /*
-                * transfer all outstanding frames that need a tx_status
-                * reports to the global tx_status queue
-                */
-
-               for (i = 0; i < ar->hw->queues; i++) {
-                       while ((skb = skb_dequeue(&info->tx_status[i]))) {
-#ifdef AR9170_QUEUE_DEBUG
-                               printk(KERN_DEBUG "%s: queueing frame in "
-                                         "global tx_status queue =>\n",
-                                      wiphy_name(ar->hw->wiphy));
-
-                               ar9170_print_txheader(ar, skb);
-#endif /* AR9170_QUEUE_DEBUG */
-                               skb_queue_tail(&ar->global_tx_status, skb);
-                       }
-               }
-               queue_delayed_work(ar->hw->workqueue, &ar->tx_status_janitor,
-                                  msecs_to_jiffies(100));
-               break;
-
-       default:
-               break;
-       }
 }
 
 static int ar9170_get_stats(struct ieee80211_hw *hw,
        int ret;
 
        mutex_lock(&ar->mutex);
-       if ((param) && !(queue > ar->hw->queues)) {
+       if ((param) && !(queue > __AR9170_NUM_TXQ)) {
                memcpy(&ar->edcf[ar9170_qos_hwmap[queue]],
                       param, sizeof(*param));
 
        mutex_init(&ar->mutex);
        spin_lock_init(&ar->cmdlock);
        spin_lock_init(&ar->tx_stats_lock);
-       skb_queue_head_init(&ar->global_tx_status);
-       skb_queue_head_init(&ar->global_tx_status_waste);
+       for (i = 0; i < __AR9170_NUM_TXQ; i++) {
+               skb_queue_head_init(&ar->tx_status[i]);
+               skb_queue_head_init(&ar->tx_pending[i]);
+       }
        ar9170_rx_reset_rx_mpdu(ar);
        INIT_WORK(&ar->filter_config_work, ar9170_set_filters);
        INIT_WORK(&ar->beacon_work, ar9170_new_beacon);
-       INIT_DELAYED_WORK(&ar->tx_status_janitor, ar9170_tx_status_janitor);
+       INIT_DELAYED_WORK(&ar->tx_janitor, ar9170_tx_janitor);
 
        /* all hw supports 2.4 GHz, so set channel to 1 by default */
        ar->channel = &ar9170_2ghz_chantable[0];