Return-path: Received: from mail-iy0-f174.google.com ([209.85.210.174]:52422 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752651Ab1ASKLP (ORCPT ); Wed, 19 Jan 2011 05:11:15 -0500 MIME-Version: 1.0 In-Reply-To: <1295430682.4685.1.camel@jlt3.sipsolutions.net> References: <1295430682.4685.1.camel@jlt3.sipsolutions.net> Date: Wed, 19 Jan 2011 17:11:14 +0700 Message-ID: Subject: Re: [2.6.38-rc1] iwlagn lock misuse... From: Daniel J Blueman To: Johannes Berg Cc: Reinette Chatre , Wey-Yi Guy , Intel Linux Wireless , linux-wireless@vger.kernel.org, Linux Kernel Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi Johannes, On 19 January 2011 16:51, Johannes Berg wrote: > On Wed, 2011-01-19 at 16:44 +0700, Daniel J Blueman wrote: >> Booting an instrumented 2.6.38-rc1 kernel with an Intel WiFi Link 5300 >> card and associating with an access point, I see a lockdep warning >> [attached]. >> >> This is essentially (struct iwl_priv)->lock being taken with >> interrupts disabled in iwl-agn-ict.c:152 [1] and the same lock taken >> with interrupts enabled in rx.c:2476 [2] (confirmed via disassembly). >> >> It feels like this would have been introduced in this commit: >> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=6e8cc38d5b05bb812f89a35bd9bf52405e67d0df > > I think you're running into a lockdep false positive, it's not actually > the same lock and lockdep confuses a few skb queue locks. Please apply > this patch > http://git.kernel.org/?p=linux/kernel/git/linville/wireless-testing.git;a=commitdiff;h=53c16b8e752e8e58f4313f1155f3afadf78311bb > and see if the problem persists. Good move; it addresses the false-positive. I hope it can hit 2.6.38-rc2. Thanks, Daniel -- Daniel J Blueman