From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: INFO: possible recursive locking detected ps2_command Date: Thu, 3 Sep 2009 20:23:43 -0700 Message-ID: <20090904035641.2B5B6526EA5@mailhub.coreip.homeip.net> References: <20080731145739.fe8923be.akpm@linux-foundation.org> <20080801030444.GB18953@anvil.corenet.prv> <1218192589.8625.88.camel@twins> <20080808082930.ZZRA012@mailhub.coreip.homeip.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-pz0-f190.google.com ([209.85.222.190]:48701 "EHLO mail-pz0-f190.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932638AbZIDDXu (ORCPT ); Thu, 3 Sep 2009 23:23:50 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Zdenek Kabelac Cc: Peter Zijlstra , Andrew Morton , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, Jiri Kosina , Rabin Vincent On Fri, Sep 04, 2009 at 12:48:45AM +0200, Zdenek Kabelac wrote: > 2008/8/8 Dmitry Torokhov : > > On Fri, Aug 08, 2008 at 12:49:49PM +0200, Peter Zijlstra wrote: > >> On Thu, 2008-07-31 at 23:04 -0400, Dmitry Torokhov wrote: > >> > On Thu, Jul 31, 2008 at 02:57:39PM -0700, Andrew Morton wrote: > >> > > > >> > > (cc linux-input) > >> > > > >> > > On Thu, 31 Jul 2008 11:41:25 +0200 > >> > > "Zdenek Kabelac" wrote: > >> > > > >> > > > Hi > >> > > > > >> > > > During mouse unplugging from psaux connector from the laptop= s' docking > >> > > > station I've got attached INFO trace. > >> > > > (laptops still has synaptics device) > >> > > > > >> > > >> > Dell? > >> > > >> > > > Also for unknown reason to me =A0psaux mouse & synaptic devi= ce do not > >> > > > work somehow together - is it hw limitation > >> > > > of /dev/input/mice =A0interface? > >> > > > (USB mouse and synaptics do work quite well together) > >> > > > > >> > > > [ INFO: possible recursive locking detected ] > >> > > > 2.6.27-rc1 #48 > >> > > > >> > > (it's 2.6.27-rc1) > >> > > > >> > > >> > Peter, here is the trace we talked about long time ago. For some= reason > >> > lockdep annotation only works once. If reconnect is forced or ps= mouse > >> > module is reloaded lockdep starts complaining about passthrough = port. > >> > >> Bit puzzling - and I don't have any ps2 hardware around to test wi= th > >> (nor do I normally use modules - but that is fixable of course). > >> > >> Does Rabin's patch help? > >> > >> =A0 http://lkml.org/lkml/2008/8/7/329 > >> > > > > I doubt it resolves problem fully because it only takes care of mod= ule > > unload. I can easily trip lockdep by reconnecting the device. Just = to > > give some more details about the problem: > > > > =A0- synaptics touchpads have a pass-through port that allows to co= nnect > > =A0 either external mouse or maybe a trackpoint device. Both device= s > > =A0 are represented by 'serio' structures and are handled by the sa= me > > =A0 driver (psmouse). > > > > =A0- as far as I know we have proper locking there and lockdep > > =A0 annotatinos were added to lockdep to reflect the nesting of the > > =A0 serio ports. > > > > =A0- if child port (pass-through port) is destroyed and recreated (= due > > =A0 to module unload, or because user requested reconnect through s= ysfs > > =A0 or system-initiated reconnect) lockdep starts complaining altho= ugh > > =A0 the new child port should still have the same "depth" as the ol= d > > =A0 one. > > >=20 > Well just noticed this issue again in my log - during resume operatio= n > - thus no external mouse connection in the game this time: >=20 External mouse does not have to be connected, the fact that you have a pass-through serio port is enough to trigger this warning. --=20 Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html