commit 5f100878786d6f12836a8c771012a7c9aa89f5e4
Author: Jiri Slaby <ku@bellona.localdomain>
Date:   Tue Jul 24 12:26:01 2007 +0200

    correct stopping/waking tx queues

diff --git a/ath.c b/ath.c
index 510f5e6..5a7fc36 100644
--- a/ath.c
+++ b/ath.c
@@ -217,11 +217,14 @@ static void ath_tx_processq(struct ath_softc *sc, struct ath_txq *txq)
 		spin_lock(&sc->txbuflock);
 		sc->tx_stats.data[txq->qnum].len--;
 		list_move_tail(&bf->list, &sc->txbuf);
+		sc->txbuf_len++;
 		spin_unlock(&sc->txbuflock);
 	}
 	if (likely(list_empty(&txq->q)))
 		txq->link = NULL;
 	spin_unlock(&txq->lock);
+	if (sc->txbuf_len > ATH_TXBUF / 5)
+		ieee80211_wake_queues(sc->hw);
 }
 
 static void ath_tasklet_tx(unsigned long data)
@@ -230,8 +233,6 @@ static void ath_tasklet_tx(unsigned long data)
 
 	ath_tx_processq(sc, sc->txq);
 
-	ieee80211_wake_queue(sc->hw, 0);
-
 	ath_led_event(sc, ATH_LED_TX);
 }
 
@@ -667,6 +668,7 @@ static void ath_tx_draintxq(struct ath_softc *sc, struct ath_txq *txq)
 		spin_lock_bh(&sc->txbuflock);
 		sc->tx_stats.data[txq->qnum].len--;
 		list_move_tail(&bf->list, &sc->txbuf);
+		sc->txbuf_len++;
 		spin_unlock_bh(&sc->txbuflock);
 	}
 	txq->link = NULL;
@@ -995,10 +997,12 @@ static int ath_tx(struct ieee80211_hw *hw, struct sk_buff *skb,
 				"dropping packet\n");
 		sc->stats.ast_tx_nobuf++;
 		spin_unlock_irqrestore(&sc->txbuflock, flags);
+		ieee80211_stop_queue(hw, ctl->queue);
 		return -1;
 	}
 	bf = list_first_entry(&sc->txbuf, struct ath_buf, list);
 	list_del(&bf->list);
+	sc->txbuf_len--;
 	if (list_empty(&sc->txbuf)) {
 		sc->stats.ast_tx_qstop++;
 		ieee80211_stop_queues(hw);
@@ -1011,6 +1015,7 @@ static int ath_tx(struct ieee80211_hw *hw, struct sk_buff *skb,
 		bf->skb = NULL;
 		spin_lock_irqsave(&sc->txbuflock, flags);
 		list_add_tail(&bf->list, &sc->txbuf);
+		sc->txbuf_len++;
 		spin_unlock_irqrestore(&sc->txbuflock, flags);
 		dev_kfree_skb_any(skb);
 		return 0;
@@ -1598,6 +1603,7 @@ static int ath_desc_alloc(struct ath_softc *sc, struct pci_dev *pdev)
 	}
 
 	INIT_LIST_HEAD(&sc->txbuf);
+	sc->txbuf_len = ATH_TXBUF;
 	for (i = 0; i < ATH_TXBUF; i++, bf++, ds += ATH_TXDESC,
 			da += ATH_TXDESC * sizeof(*ds)) {
 		bf->desc = ds;
diff --git a/ath.h b/ath.h
index b83ec04..613db78 100644
--- a/ath.h
+++ b/ath.h
@@ -194,6 +194,7 @@ struct ath_softc {
 #endif
 	struct list_head	txbuf;		/* transmit buffer */
 	spinlock_t		txbuflock;
+	unsigned int		txbuf_len;	/* buf count in txbuf list */
 	struct ath_txq		txqs[2];	/* beacon and tx */
 #ifdef UNUSED
 	struct ath_txq		*sc_ac2q[5];	/* WME AC -> h/w q map */