From c18d6e16ea2334b2d379f7a1e1778427b17666e6 Mon Sep 17 00:00:00 2001
From: nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Tue, 1 Jun 2010 17:38:01 +0000
Subject: [PATCH] ath9k: fix queue stopping/starting logic, should slightly
reduce RAM usage under load and make throughput more smooth
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@21650 3c298f89-4303-0410-b956-a3cf2f4a3e73
---
.../patches/530-ath9k_queue_fill.patch | 144 ++++++++++++++++++
1 file changed, 144 insertions(+)
create mode 100644 package/mac80211/patches/530-ath9k_queue_fill.patch
diff --git a/package/mac80211/patches/530-ath9k_queue_fill.patch b/package/mac80211/patches/530-ath9k_queue_fill.patch
new file mode 100644
index 000000000..172fba400
--- /dev/null
+++ b/package/mac80211/patches/530-ath9k_queue_fill.patch
@@ -0,0 +1,144 @@
+--- a/drivers/net/wireless/ath/ath9k/ath9k.h
++++ b/drivers/net/wireless/ath/ath9k/ath9k.h
+@@ -137,6 +137,8 @@ void ath_descdma_cleanup(struct ath_soft
+ #define ATH_MAX_ANTENNA 3
+ #define ATH_RXBUF 512
+ #define ATH_TXBUF 512
++#define ATH_TXBUF_RESERVE 5
++#define ATH_MAX_QDEPTH (ATH_TXBUF / 4 - ATH_TXBUF_RESERVE)
+ #define ATH_TXMAXTRY 13
+ #define ATH_MGT_TXMAXTRY 4
+
+@@ -205,6 +207,7 @@ struct ath_txq {
+ struct list_head txq_fifo_pending;
+ u8 txq_headidx;
+ u8 txq_tailidx;
++ int pending_frames;
+ };
+
+ struct ath_atx_ac {
+@@ -242,6 +245,7 @@ struct ath_buf {
+ struct ath_buf_state bf_state;
+ dma_addr_t bf_dmacontext;
+ struct ath_wiphy *aphy;
++ struct ath_txq *txq;
+ };
+
+ struct ath_atx_tid {
+@@ -331,7 +335,6 @@ void ath_tx_node_cleanup(struct ath_soft
+ void ath_txq_schedule(struct ath_softc *sc, struct ath_txq *txq);
+ int ath_tx_init(struct ath_softc *sc, int nbufs);
+ void ath_tx_cleanup(struct ath_softc *sc);
+-struct ath_txq *ath_test_get_txq(struct ath_softc *sc, struct sk_buff *skb);
+ int ath_txq_update(struct ath_softc *sc, int qnum,
+ struct ath9k_tx_queue_info *q);
+ int ath_tx_start(struct ieee80211_hw *hw, struct sk_buff *skb,
+--- a/drivers/net/wireless/ath/ath9k/xmit.c
++++ b/drivers/net/wireless/ath/ath9k/xmit.c
+@@ -986,32 +986,6 @@ int ath_tx_get_qnum(struct ath_softc *sc
+ return qnum;
+ }
+
+-struct ath_txq *ath_test_get_txq(struct ath_softc *sc, struct sk_buff *skb)
+-{
+- struct ath_txq *txq = NULL;
+- u16 skb_queue = skb_get_queue_mapping(skb);
+- int qnum;
+-
+- qnum = ath_get_hal_qnum(skb_queue, sc);
+- txq = &sc->tx.txq[qnum];
+-
+- spin_lock_bh(&txq->axq_lock);
+-
+- if (txq->axq_depth >= (ATH_TXBUF - 20)) {
+- ath_print(ath9k_hw_common(sc->sc_ah), ATH_DBG_XMIT,
+- "TX queue: %d is full, depth: %d\n",
+- qnum, txq->axq_depth);
+- ath_mac80211_stop_queue(sc, skb_queue);
+- txq->stopped = 1;
+- spin_unlock_bh(&txq->axq_lock);
+- return NULL;
+- }
+-
+- spin_unlock_bh(&txq->axq_lock);
+-
+- return txq;
+-}
+-
+ int ath_txq_update(struct ath_softc *sc, int qnum,
+ struct ath9k_tx_queue_info *qinfo)
+ {
+@@ -1811,6 +1785,7 @@ int ath_tx_start(struct ieee80211_hw *hw
+ struct ath_wiphy *aphy = hw->priv;
+ struct ath_softc *sc = aphy->sc;
+ struct ath_common *common = ath9k_hw_common(sc->sc_ah);
++ struct ath_txq *txq = txctl->txq;
+ struct ath_buf *bf;
+ int r;
+
+@@ -1820,10 +1795,16 @@ int ath_tx_start(struct ieee80211_hw *hw
+ return -1;
+ }
+
++ bf->txq = txctl->txq;
++ spin_lock_bh(&bf->txq->axq_lock);
++ if (++bf->txq->pending_frames > ATH_MAX_QDEPTH && !txq->stopped) {
++ ath_mac80211_stop_queue(sc, skb_get_queue_mapping(skb));
++ txq->stopped = 1;
++ }
++ spin_unlock_bh(&bf->txq->axq_lock);
++
+ r = ath_tx_setup_buffer(hw, bf, skb, txctl);
+ if (unlikely(r)) {
+- struct ath_txq *txq = txctl->txq;
+-
+ ath_print(common, ATH_DBG_FATAL, "TX mem alloc failure\n");
+
+ /* upon ath_tx_processq() this TX queue will be resumed, we
+@@ -1831,7 +1812,7 @@ int ath_tx_start(struct ieee80211_hw *hw
+ * we will at least have to run TX completionon one buffer
+ * on the queue */
+ spin_lock_bh(&txq->axq_lock);
+- if (sc->tx.txq[txq->axq_qnum].axq_depth > 1) {
++ if (!txq->stopped && txq->axq_depth > 1) {
+ ath_mac80211_stop_queue(sc, skb_get_queue_mapping(skb));
+ txq->stopped = 1;
+ }
+@@ -1972,6 +1953,13 @@ static void ath_tx_complete_buf(struct a
+ tx_flags |= ATH_TX_XRETRY;
+ }
+
++ if (bf->txq) {
++ spin_lock_bh(&bf->txq->axq_lock);
++ bf->txq->pending_frames--;
++ spin_unlock_bh(&bf->txq->axq_lock);
++ bf->txq = NULL;
++ }
++
+ dma_unmap_single(sc->dev, bf->bf_dmacontext, skb->len, DMA_TO_DEVICE);
+ ath_tx_complete(sc, skb, bf->aphy, tx_flags);
+ ath_debug_stat_tx(sc, txq, bf, ts);
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -1026,6 +1026,7 @@ static int ath9k_tx(struct ieee80211_hw
+ struct ath_tx_control txctl;
+ int padpos, padsize;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
++ int qnum;
+
+ if (aphy->state != ATH_WIPHY_ACTIVE && aphy->state != ATH_WIPHY_SCAN) {
+ ath_print(common, ATH_DBG_XMIT,
+@@ -1098,11 +1099,8 @@ static int ath9k_tx(struct ieee80211_hw
+ memmove(skb->data, skb->data + padsize, padpos);
+ }
+
+- /* Check if a tx queue is available */
+-
+- txctl.txq = ath_test_get_txq(sc, skb);
+- if (!txctl.txq)
+- goto exit;
++ qnum = ath_get_hal_qnum(skb_get_queue_mapping(skb), sc);
++ txctl.txq = &sc->tx.txq[qnum];
+
+ ath_print(common, ATH_DBG_XMIT, "transmitting packet, skb: %p\n", skb);
+
--
2.20.1