ath9k: fix pending tx frames accounting

Packets originally buffered for the regular hardware tx queues can end
up being transmitted through the U-APSD queue (via PS-Poll or U-APSD).
When packets are dropped due to retransmit failures, the pending frames
counter is not always updated properly.
Fix this by keeping track of the queue that a frame was accounted for in
the ath_frame_info struct, and using that on completion to decide
whether the counter should be updated.
This fixes some spurious transmit queue hangs.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 11b5e4d..7fc13a8 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -182,7 +182,8 @@ struct ath_atx_ac {
 
 struct ath_frame_info {
        struct ath_buf *bf;
-       int framelen;
+       u16 framelen;
+       s8 txq;
        enum ath9k_key_type keytype;
        u8 keyix;
        u8 rtscts_rate;

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index d4927c9..3611529 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -157,15 +157,14 @@ static void ath_txq_skb_done(struct ath_softc *sc, struct ath_txq *txq,
                             struct sk_buff *skb)
 {
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-       int q, hw_queue;
-
-       q = skb_get_queue_mapping(skb);
-       if (txq == sc->tx.uapsdq)
-               txq = sc->tx.txq_map[q];
+       struct ath_frame_info *fi = get_frame_info(skb);
+       int hw_queue;
+       int q = fi->txq;
 
-       if (txq != sc->tx.txq_map[q])
+       if (q < 0)
                return;
 
+       txq = sc->tx.txq_map[q];
        if (WARN_ON(--txq->pending_frames < 0))
                txq->pending_frames = 0;
 
@@ -2036,6 +2035,7 @@ static void setup_frame_info(struct ieee80211_hw *hw,
                an = (struct ath_node *) sta->drv_priv;
 
        memset(fi, 0, sizeof(*fi));
+       fi->txq = -1;
        if (hw_key)
                fi->keyix = hw_key->hw_key_idx;
        else if (an && ieee80211_is_data(hdr->frame_control) && an->ps_key > 0)
@@ -2187,6 +2187,7 @@ int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        struct ieee80211_sta *sta = txctl->sta;
        struct ieee80211_vif *vif = info->control.vif;
+       struct ath_frame_info *fi = get_frame_info(skb);
        struct ath_vif *avp = NULL;
        struct ath_softc *sc = hw->priv;
        struct ath_txq *txq = txctl->txq;
@@ -2216,11 +2217,13 @@ int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
        hw_queue = (info->hw_queue >= sc->hw->queues - 2) ? q : info->hw_queue;
 
        ath_txq_lock(sc, txq);
-       if (txq == sc->tx.txq_map[q] &&
-           ++txq->pending_frames > sc->tx.txq_max_pending[q] &&
-           !txq->stopped) {
-               ieee80211_stop_queue(sc->hw, hw_queue);
-               txq->stopped = true;
+       if (txq == sc->tx.txq_map[q]) {
+               fi->txq = q;
+               if (++txq->pending_frames > sc->tx.txq_max_pending[q] &&
+                   !txq->stopped) {
+                       ieee80211_stop_queue(sc->hw, hw_queue);
+                       txq->stopped = true;
+               }
        }
 
        queue = ieee80211_is_data_present(hdr->frame_control);