A ref-counting bug emerged after testing ar9170usb's HT
implementation on a bigger SMP/SMT system without the usual
_debugging_ overhead.
Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
---
Just in case: all patches are for wireless-testing.
I don't think it's critical, since the A-MPDU can't
be enabled in vanilla anyway...
---
diff --git a/drivers/net/wireless/ath/ar9170/ar9170.h b/drivers/net/wireless/ath/ar9170/ar9170.h
index ec034af..9f94598 100644
--- a/drivers/net/wireless/ath/ar9170/ar9170.h
+++ b/drivers/net/wireless/ath/ar9170/ar9170.h
@@ -231,7 +231,7 @@ struct ar9170 {
struct sk_buff_head tx_status_ampdu;
spinlock_t tx_ampdu_list_lock;
struct list_head tx_ampdu_list;
- unsigned int tx_ampdu_pending;
+ atomic_t tx_ampdu_pending;
/* rxstream mpdu merge */
struct ar9170_rxstream_mpdu_merge rx_mpdu;
diff --git a/drivers/net/wireless/ath/ar9170/main.c b/drivers/net/wireless/ath/ar9170/main.c
index de0ba2b..7e59b82 100644
--- a/drivers/net/wireless/ath/ar9170/main.c
+++ b/drivers/net/wireless/ath/ar9170/main.c
@@ -414,9 +414,9 @@ static void ar9170_tx_ampdu_callback(struct ar9170 *ar, struct sk_buff *skb)
skb_queue_tail(&ar->tx_status_ampdu, skb);
ar9170_tx_fake_ampdu_status(ar);
- ar->tx_ampdu_pending--;
- if (!list_empty(&ar->tx_ampdu_list) && !ar->tx_ampdu_pending)
+ if (atomic_dec_and_test(&ar->tx_ampdu_pending) &&
+ !list_empty(&ar->tx_ampdu_list))
ar9170_tx_ampdu(ar);
}
@@ -1248,6 +1248,7 @@ static int ar9170_op_start(struct ieee80211_hw *hw)
ar->global_ampdu_density = 6;
ar->global_ampdu_factor = 3;
+ atomic_set(&ar->tx_ampdu_pending, 0);
ar->bad_hw_nagger = jiffies;
err = ar->open(ar);
@@ -1773,7 +1774,7 @@ static void ar9170_tx(struct ar9170 *ar)
msecs_to_jiffies(AR9170_TX_TIMEOUT);
if (arinfo->flags == AR9170_TX_FLAG_BLOCK_ACK)
- ar->tx_ampdu_pending++;
+ atomic_inc(&ar->tx_ampdu_pending);
#ifdef AR9170_QUEUE_DEBUG
printk(KERN_DEBUG "%s: send frame q:%d =>\n",
@@ -1784,7 +1785,7 @@ static void ar9170_tx(struct ar9170 *ar)
err = ar->tx(ar, skb);
if (unlikely(err)) {
if (arinfo->flags == AR9170_TX_FLAG_BLOCK_ACK)
- ar->tx_ampdu_pending--;
+ atomic_dec(&ar->tx_ampdu_pending);
frames_failed++;
dev_kfree_skb_any(skb);
@@ -1931,7 +1932,7 @@ int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
if (info->flags & IEEE80211_TX_CTL_AMPDU) {
bool run = ar9170_tx_ampdu_queue(ar, skb);
- if (run || !ar->tx_ampdu_pending)
+ if (run || !atomic_read(&ar->tx_ampdu_pending))
ar9170_tx_ampdu(ar);
} else {
unsigned int queue = skb_get_queue_mapping(skb);
--
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