From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-iw0-f178.google.com ([209.85.223.178]:41041 "EHLO mail-iw0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754235AbZI3XUM convert rfc822-to-8bit (ORCPT ); Wed, 30 Sep 2009 19:20:12 -0400 Received: by iwn8 with SMTP id 8so3938338iwn.33 for ; Wed, 30 Sep 2009 16:20:16 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <43e72e890909301612v5079c9bco9ac8529f77a7c67a@mail.gmail.com> References: <43e72e890909291224t26b7e6cbmc78976165bd1bb88@mail.gmail.com> <43e72e890909301612v5079c9bco9ac8529f77a7c67a@mail.gmail.com> From: "Luis R. Rodriguez" Date: Wed, 30 Sep 2009 16:19:56 -0700 Message-ID: <43e72e890909301619t4c0a26feq935cfef65ebf1493@mail.gmail.com> Subject: Re: SME warning on 2.6.32-rc To: linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, Sep 30, 2009 at 4:12 PM, Luis R. Rodriguez wrote: > On Tue, Sep 29, 2009 at 12:24 PM, Luis R. Rodriguez wrote: >> I believe the problem comes from the assumption from cfg80211 that >> previous deauthentications would have gone through before we run >> __cfg80211_disconnected() and are using wext or nl80211 >> connec/disconnectt. Under certain conditions (clearly not known yet) >> this is not true and we'll end up asking mac80211 to deauthenticate us >> from a BSS we already deauthenticated to end end up with an -ENOLINK >> on our mac80211 cfg80211 deauth ops. It seems this race was expected >> all along on mac80211 ieee80211_mgd_deauth(): >> >>        /* >>         * cfg80211 should catch this ... but it's racy since >>         * we can receive a deauth frame, process it, hand it >>         * to cfg80211 while that's in a locked section already >>         * trying to tell us that the user wants to disconnect. >>         */ >>        if (!bssid) { >>                mutex_unlock(&ifmgd->mtx); >>                return -ENOLINK; >>        } >> >> So it seems we do need to address that race but I'm not yet sure how. >> >> Here is a warning from the latest wireless-testing. Unfortunately I >> cannot reproduce in a systematic way, I've tried even different boot >> configuration (mem=300M) and CPU pegged at 800 MHz thinking the race >> occurs when mac80211 takes its sweet time deathenticating but that >> wasn't the case. > > OK so I just got this again today with a cardbus card. The curious > thing to see was that it happened when I rmmod'd ath9k right after > these messages: > > [  234.481226] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 > AR_DIAG_SW=0x40000020 > [  234.928823] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 > AR_DIAG_SW=0x40000020 > [  237.064792] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 > AR_DIAG_SW=0x40000020 > [  310.676842] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 > AR_DIAG_SW=0x40000020 Mind you I am not sure if its the Cardbus card, it could be busted, I've seen some strange issues with it before. Luis