From a129099ef7afbe6fe73ffb9d8a8805b559559d19 Mon Sep 17 00:00:00 2001
From: nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Sun, 7 Apr 2013 22:05:45 +0000
Subject: ath9k: fix a tx processing race condition on AR9300+
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36267 3c298f89-4303-0410-b956-a3cf2f4a3e73
---
package/mac80211/patches/300-pending_work.patch | 74 +++++++++++++++++++++++++
1 file changed, 74 insertions(+)
diff --git a/package/mac80211/patches/300-pending_work.patch b/package/mac80211/patches/300-pending_work.patch
index 7558c3d1a..569bf7f06 100644
--- a/package/mac80211/patches/300-pending_work.patch
+++ b/package/mac80211/patches/300-pending_work.patch
@@ -1036,3 +1036,77 @@
dev_err(priv->dev, "ath9k_htc: Please upgrade to FW version %d.%d\n",
MAJOR_VERSION_REQ, MINOR_VERSION_REQ);
return -EINVAL;
+--- a/drivers/net/wireless/ath/ath9k/xmit.c
++++ b/drivers/net/wireless/ath/ath9k/xmit.c
+@@ -516,8 +516,7 @@ static void ath_tx_complete_aggr(struct
+ * not a holding desc.
+ */
+ INIT_LIST_HEAD(&bf_head);
+- if ((sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) ||
+- bf_next != NULL || !bf_last->bf_stale)
++ if (bf_next != NULL || !bf_last->bf_stale)
+ list_move_tail(&bf->list, &bf_head);
+
+ if (!txpending || (tid->state & AGGR_CLEANUP)) {
+@@ -537,8 +536,7 @@ static void ath_tx_complete_aggr(struct
+ !txfail);
+ } else {
+ /* retry the un-acked ones */
+- if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) &&
+- bf->bf_next == NULL && bf_last->bf_stale) {
++ if (bf->bf_next == NULL && bf_last->bf_stale) {
+ struct ath_buf *tbf;
+
+ tbf = ath_clone_txbuf(sc, bf_last);
+@@ -2264,6 +2262,7 @@ void ath_tx_edma_tasklet(struct ath_soft
+ struct ath_txq *txq;
+ struct ath_buf *bf, *lastbf;
+ struct list_head bf_head;
++ struct list_head *fifo_list;
+ int status;
+
+ for (;;) {
+@@ -2291,20 +2290,24 @@ void ath_tx_edma_tasklet(struct ath_soft
+
+ TX_STAT_INC(txq->axq_qnum, txprocdesc);
+
+- if (list_empty(&txq->txq_fifo[txq->txq_tailidx])) {
++ fifo_list = &txq->txq_fifo[txq->txq_tailidx];
++ if (list_empty(fifo_list)) {
+ ath_txq_unlock(sc, txq);
+ return;
+ }
+
+- bf = list_first_entry(&txq->txq_fifo[txq->txq_tailidx],
+- struct ath_buf, list);
++ bf = list_first_entry(fifo_list, struct ath_buf, list);
++ if (bf->bf_stale) {
++ list_del(&bf->list);
++ ath_tx_return_buffer(sc, bf);
++ bf = list_first_entry(fifo_list, struct ath_buf, list);
++ }
++
+ lastbf = bf->bf_lastbf;
+
+ INIT_LIST_HEAD(&bf_head);
+- list_cut_position(&bf_head, &txq->txq_fifo[txq->txq_tailidx],
+- &lastbf->list);
+-
+- if (list_empty(&txq->txq_fifo[txq->txq_tailidx])) {
++ if (list_is_last(&lastbf->list, fifo_list)) {
++ list_splice_tail_init(fifo_list, &bf_head);
+ INCR(txq->txq_tailidx, ATH_TXFIFO_DEPTH);
+
+ if (!list_empty(&txq->axq_q)) {
+@@ -2315,6 +2318,11 @@ void ath_tx_edma_tasklet(struct ath_soft
+ list_splice_tail_init(&txq->axq_q, &bf_q);
+ ath_tx_txqaddbuf(sc, txq, &bf_q, true);
+ }
++ } else {
++ lastbf->bf_stale = true;
++ if (bf != lastbf)
++ list_cut_position(&bf_head, fifo_list,
++ lastbf->list.prev);
+ }
+
+ ath_tx_process_buffer(sc, txq, &ts, bf, &bf_head);
--
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