Re: recursive locking on wireless-testing.

[Felix Fietkau <nbd@openwrt.org>]

On 2010-11-17 10:19 PM, Ben Greear wrote:
> I found this while testing wpa_supplicant that shares scan results.
> The kernel has no scan-sharing hacks in it..just a few patches
> I've been using for a while (and the deadlock prevention patch
> previously mentioned in other threads).
> 
> 
> Nov 17 13:16:25 ath9k kernel: ieee80211 wiphy0: Removed STA 00:14:d1:c6:d2:54
> Nov 17 13:16:25 ath9k kernel: ieee80211 wiphy0: Destroyed STA 00:14:d1:c6:d2:54
> 
> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.37-rc1-wl+ #48
> ---------------------------------------------
This should fix it. ath_tx_complete is already called with the txq locked.

--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1830,10 +1830,8 @@ static void ath_tx_complete(struct ath_s
 	else {
 		q = skb_get_queue_mapping(skb);
 		if (txq == sc->tx.txq_map[q]) {
-			spin_lock_bh(&txq->axq_lock);
 			if (WARN_ON(--txq->pending_frames < 0))
 				txq->pending_frames = 0;
-			spin_unlock_bh(&txq->axq_lock);
 		}

 		ieee80211_tx_status(hw, skb);