2014-07-16 19:10:15

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH] 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: [email protected]
Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 3 ++-
drivers/net/wireless/ath/ath9k/xmit.c | 25 ++++++++++++++-----------
2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 11b5e4d..7fc13a8 100644
--- 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
--- 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);
--
1.8.5.2 (Apple Git-48)