Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752656Ab1BFNBy (ORCPT ); Sun, 6 Feb 2011 08:01:54 -0500 Received: from mail-iw0-f174.google.com ([209.85.214.174]:64857 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752304Ab1BFNBw convert rfc822-to-8bit (ORCPT ); Sun, 6 Feb 2011 08:01:52 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=rTAN312Vr6khUO0OkRsouOTsP5iFirKEHRIIlsYCWKY9QvV3+f8IX0YuTeL0zg1anm 8lZzjIuLakT3DBSZ3f8CgF3Qg5HGoxbnwQ/hLACG/KunvewM0tG8Z9TSRffgXAYVRlRs GGyTn+5AWlCaH/nwe3U/8eUze/qV2TM3iVQlY= MIME-Version: 1.0 In-Reply-To: <201102061303.13390.rjw@sisk.pl> References: <201102061301.56097.rjw@sisk.pl> <201102061303.13390.rjw@sisk.pl> Date: Sun, 6 Feb 2011 22:01:51 +0900 Message-ID: Subject: Re: [BUG] usb_set_device_state From: Minchan Kim To: "Rafael J. Wysocki" Cc: Alan Stern , linux kernel mailing list , Greg Kroah-Hartman , Andrew Morton Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2109 Lines: 54 On Sun, Feb 6, 2011 at 9:03 PM, Rafael J. Wysocki wrote: > On Sunday, February 06, 2011, Rafael J. Wysocki wrote: >> On Sunday, February 06, 2011, Alan Stern wrote: >> > On Sun, 6 Feb 2011, Rafael J. Wysocki wrote: >> > >> > > On Saturday, February 05, 2011, Alan Stern wrote: >> > > > On Sun, 6 Feb 2011, Minchan Kim wrote: >> > > > >> > > > > I got following message during booting mmotm-02-04. >> > ... >> > > > > It seems usb_set_device_state disable irq by spin_lock_irqsave. >> > > > > But it calls device_set_wakeup_capable which ends up calling sysfs_merge_group. >> > > > > It calls mutex_lock. :( >> > > > > >> > > > > Is it already known BUG? >> > > > >> > > > No, it was newly introduced by changes to the >> > > > device_set_wakeup_capable() routine.  Rafael, this sort of problem may >> > > > occur in other places too, since previously there was no requirement >> > > > that device_set_wakeup_capable() be called in process context. >> > > >> > > I'm aware of that, but it's only happend in a handful of network drivers so far. >> > > >> > > I think this is a new case in -mm, though, isn't it? >> > >> > I'm not sure.  The USB core does call device_set_wakeup_capable() >> > while holding one or more spinlocks in usb_set_device_state(), and that >> > routine is called in several places.  You ought to be able to duplicate >> > the error on your own system simply by plugging in a USB hub. >> >> No, I'm not.  At least not with 2.6.37. >> >> Also, I think the problem would have been reported before if it had been that >> easy to reproduce with the mainline kernel. > > Or do I need to enable a specific CONFIG_ option to reproduce it? > > Rafael > When I am googling, I found https://lkml.org/lkml/2011/1/14/440. Maybe the bug is caused by that. It is in linux-next and mmotm, not linus tree. -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/