Commit 02bdf5b4 authored by Christian Lamparter's avatar Christian Lamparter Committed by John W. Linville
Browse files

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: default avatarChristian Lamparter <chunkeey@googlemail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 4ad177b5

drivers/net/wireless/ath/ar9170/ar9170.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/net/wireless/ath/ar9170/main.c

+6 −5
Original line number Diff line number Diff line
@@ -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);