From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nbd.name ([46.4.11.11]:38541 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756206Ab0KRJxf (ORCPT ); Thu, 18 Nov 2010 04:53:35 -0500 Message-ID: <4CE4F79B.3000500@openwrt.org> Date: Thu, 18 Nov 2010 10:53:31 +0100 From: Felix Fietkau MIME-Version: 1.0 To: Ben Greear CC: "linux-wireless@vger.kernel.org" Subject: Re: recursive locking on wireless-testing. References: <4CE446E3.3090604@candelatech.com> <4CE47563.2090803@openwrt.org> <4CE47978.8050405@candelatech.com> In-Reply-To: <4CE47978.8050405@candelatech.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2010-11-18 1:55 AM, Ben Greear wrote: > On 11/17/2010 04:37 PM, Felix Fietkau wrote: >> 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); > > How about this instead of the other patch? --- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -163,6 +163,7 @@ static void ath_tx_flush_tid(struct ath_ bf = list_first_entry(&tid->buf_q, struct ath_buf, list); list_move_tail(&bf->list, &bf_head); + spin_unlock_bh(&txq->axq_lock); fi = get_frame_info(bf->bf_mpdu); if (fi->retries) { ath_tx_update_baw(sc, tid, fi->seqno); @@ -170,6 +171,7 @@ static void ath_tx_flush_tid(struct ath_ } else { ath_tx_send_normal(sc, txq, tid, &bf_head); } + spin_lock_bh(&txq->axq_lock); } spin_unlock_bh(&txq->axq_lock);