From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751547AbXAUNTc (ORCPT ); Sun, 21 Jan 2007 08:19:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751571AbXAUNTc (ORCPT ); Sun, 21 Jan 2007 08:19:32 -0500 Received: from mx3.mail.ru ([194.67.23.149]:6870 "EHLO mx3.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751538AbXAUNTb (ORCPT ); Sun, 21 Jan 2007 08:19:31 -0500 From: Andrey Borzenkov To: Len Brown Subject: Re: 2.6.20-rc5: BUG: lock held at task exit time! (pm_mutex){--..}, at: [] enter_state+0x3f/0x170 Date: Sun, 21 Jan 2007 16:19:25 +0300 User-Agent: KMail/1.9.5 Cc: linux-pm@lists.osdl.org, linux-usb-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <200701162122.42581.arvidjaar@mail.ru> <200701161529.28110.lenb@kernel.org> In-Reply-To: <200701161529.28110.lenb@kernel.org> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200701211619.26782.arvidjaar@mail.ru> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Tuesday 16 January 2007 23:29, Len Brown wrote: > On Tuesday 16 January 2007 13:22, Andrey Borzenkov wrote: > > I have Toshiba Portege 4000 that almost always hangs dead resuming from > > STR. This was better before 2.6.18, since then STR is unusable. Sometimes > > it manages to resume; yesterday I got on console and in dmesg: > > > > ===================================== > > [ BUG: lock held at task exit time! ] > > ------------------------------------- > > echo/28793 is exiting with locks still held! > > 1 lock held by echo/28793: > > #0: (pm_mutex){--..}, at: [] enter_state+0x3f/0x170 > > > > stack backtrace: > > [] show_trace_log_lvl+0x1a/0x30 > > [] show_trace+0x12/0x20 > > [] dump_stack+0x16/0x20 > > [] debug_check_no_locks_held+0x87/0x90 > > [] do_exit+0x4db/0x820 > > [] do_group_exit+0x29/0x70 > > [] sys_exit_group+0xf/0x20 > > [] sysenter_past_esp+0x5f/0x99 > > ======================= > > the global pm_mutex that this refers to is used in generic PM code, not USB > code. > > enter_state() grabs it at the beginning of the suspend, and releases it > when resume is completed. > > The mystery is why echo is exiting before enter_state() completes. > > >> if ! (/bin/echo $PARAM > $FILE &) ;then > >> ret=1 > >> fi > > Same if you don't put the echo in the background here? > I just tried once more on 2.6.20-rc5 with boot ... init=/bin/sh mount -t sysfs sysfs /sys echo mem > /proc/power/state this hung dead on resume - not a single message (kernel was compiled with PM_DEBUG). I usually do not get any messages at all. I believe it was two times I got anything; one is quoted in bug report and second here. - -andrey > > I have a bug report about resume issue but I may have wrongly attributed > > it to ACPI: http://bugzilla.kernel.org/show_bug.cgi?id=7499 > > hard to say if the failure is related to ACPI or not at this point -- > though it is not unusual for people to assume that STR and ACPI > are synonyms, so that if STR doesn't work it must be due to ACPI > rather than generic PM code or drivers. > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iD8DBQFFs2heR6LMutpd94wRAqS7AJ0TMRb12cEgKrH0o/mW/sF1oNJ9CwCglx3z HhzT2c3bAjBbNT7pOyCbATE= =pp1M -----END PGP SIGNATURE-----