From 02bdf5b48a2cd90a5d036eab68e6f65adb200140 Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Sat, 17 Oct 2009 21:56:43 +0200 Subject: [PATCH] ar9170: atomic pending A-MPDU counter 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 Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ar9170/ar9170.h | 2 +- drivers/net/wireless/ath/ar9170/main.c | 11 ++++++----- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/ath/ar9170/ar9170.h b/drivers/net/wireless/ath/ar9170/ar9170.h index ec034af26980..9f9459860d82 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 de0ba2bf7691..7e59b82e64d3 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);