From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759152Ab3BXTA1 (ORCPT ); Sun, 24 Feb 2013 14:00:27 -0500 Received: from bues.ch ([80.190.117.144]:41838 "EHLO bues.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755372Ab3BXTA0 (ORCPT ); Sun, 24 Feb 2013 14:00:26 -0500 X-Greylist: delayed 1645 seconds by postgrey-1.27 at vger.kernel.org; Sun, 24 Feb 2013 14:00:26 EST Date: Sun, 24 Feb 2013 19:32:39 +0100 From: Michael =?UTF-8?B?QsO8c2No?= To: Larry Finger Cc: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= , linux-wireless , b43-dev , LKML Subject: Re: Lockdep splat when unloading b43 Message-ID: <20130224193239.3517e6ac@milhouse> In-Reply-To: <512A4E83.5090901@lwfinger.net> References: <512A4E83.5090901@lwfinger.net> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 24 Feb 2013 11:31:47 -0600 Larry Finger wrote: > With the current wireless-testing tree, unloading b43 produces the lockdep log > splat copied below. My understanding of locking is deficient, and I would like > to learn. Any help on understanding this problem is appreciated. A few questions: Is there any reason for using the global workqueue and not mac80211's workqueue? Why is the workqueue cancelled in the core_stop callback? Wouldn't it make more sense to cancel it in bcma_remove/ssb_remove? This would probably fix the circular dependency. But I'm not entirely sure, because I'm not that familiar with the code anymore. -- Michael