From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.candelatech.com ([208.74.158.172]:37780 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753217Ab0KRAzX (ORCPT ); Wed, 17 Nov 2010 19:55:23 -0500 Message-ID: <4CE47978.8050405@candelatech.com> Date: Wed, 17 Nov 2010 16:55:20 -0800 From: Ben Greear MIME-Version: 1.0 To: Felix Fietkau CC: "linux-wireless@vger.kernel.org" Subject: Re: recursive locking on wireless-testing. References: <4CE446E3.3090604@candelatech.com> <4CE47563.2090803@openwrt.org> In-Reply-To: <4CE47563.2090803@openwrt.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: 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); I restarted a few times, and haven't see any lockdep errors. I did see the WARN_ON inside that lock hit, however: ------------[ cut here ]------------ WARNING: at /home/greearb/git/linux.wireless-testing/drivers/net/wireless/ath/ath9k/xmit.c:1833 ath_tx_complete_buf+0x1d5/0x240 [ath9k]() Hardware name: PDSBM Modules linked in: aes_i586 aes_generic 8021q garp stp llc michael_mic macvlan pktgen nfs lockd fscache nfs_acl auth_rpcgss sunrpc p4_clockmod ipv6 uinput arc4 ecb e1000e ath9k mac80211 ath9k_common ath9k_hw ath i2c_i801 cfg80211 iTCO_wdt iTCO_vendor_support pcspkr microcode i915 drm_kms_helper drm i2c_algo_bit i2c_core video output [last unloaded: ipt_addrtype] Pid: 0, comm: swapper Tainted: P 2.6.37-rc2-wl+ #50 Call Trace: [<78436f25>] warn_slowpath_common+0x77/0x8c [] ? ath_tx_complete_buf+0x1d5/0x240 [ath9k] [] ? ath_tx_complete_buf+0x1d5/0x240 [ath9k] [<78436f57>] warn_slowpath_null+0x1d/0x1f [] ath_tx_complete_buf+0x1d5/0x240 [ath9k] [<7843c24b>] ? _local_bh_enable_ip+0x9d/0xa6 [] ath_tx_tasklet+0x242/0x2b6 [ath9k] [] ath9k_tasklet+0xb9/0x127 [ath9k] [<7843bb0d>] tasklet_action+0x88/0xe3 [<7843c089>] __do_softirq+0x85/0x142 [<7843c004>] ? __do_softirq+0x0/0x142 [<7843beab>] ? irq_exit+0x35/0x69 [<78404245>] ? do_IRQ+0x8e/0xa2 [<7844e97c>] ? hrtimer_start+0x22/0x28 [<784036ae>] ? common_interrupt+0x2e/0x40 [<78408a12>] ? mwait_idle+0x59/0x69 [<78402417>] ? cpu_idle+0x4e/0x6b [<78779419>] ? rest_init+0xa1/0xa7 [<78779378>] ? rest_init+0x0/0xa7 [<78992949>] ? start_kernel+0x334/0x33a [<7899244f>] ? unknown_bootoption+0x0/0x190 [<789920e2>] ? i386_start_kernel+0xe2/0xea ---[ end trace a659d7b152ca5d4f ]--- Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com