Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753865AbbGIRkv (ORCPT ); Thu, 9 Jul 2015 13:40:51 -0400 Received: from lists.s-osg.org ([54.187.51.154]:40427 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751976AbbGIRkn (ORCPT ); Thu, 9 Jul 2015 13:40:43 -0400 Message-ID: <559EB218.80404@osg.samsung.com> Date: Thu, 09 Jul 2015 11:40:40 -0600 From: Shuah Khan Organization: Samsung Open Source Group User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Greg Kroah-Hartman CC: Linus Torvalds , Ming Lei , Shuah Khan , Linux Kernel Mailing List Subject: Re: Linux 4.2-rc1 References: <559E72B1.2050903@osg.samsung.com> <559E7AA4.6020602@osg.samsung.com> <20150709144540.GA27723@kroah.com> In-Reply-To: <20150709144540.GA27723@kroah.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1843 Lines: 51 On 07/09/2015 08:45 AM, Greg Kroah-Hartman wrote: > On Thu, Jul 09, 2015 at 07:44:04AM -0600, Shuah Khan wrote: >> On 07/09/2015 07:10 AM, Shuah Khan wrote: >>> On 07/08/2015 09:17 PM, Linus Torvalds wrote: >>>> On Wed, Jul 8, 2015 at 5:58 PM, Ming Lei wrote: >>>>> On Thu, Jul 9, 2015 at 1:29 AM, Linus Torvalds >>>>> wrote: >>>>>> Also, it looks like you need to hold the "fw_lock" to even look at >>>>>> that pointer, since the buffer can get reallocated etc. >>>>> >>>>> Yes, the above code with holding 'fw_lock' is right fix for the issue since >>>>> sysfs read can happen anytime, and there is one race between firmware >>>>> request abort and reading uevent of sysfs. >>>> >>>> So if fw_priv->buf is NULL, what should we do? >>>> >>>> Should we skip the TIMEOUT= and ASYNC= fields too? >>>> >>>> Something like the attached, perhaps? >>>> >>>> Shuah, how reproducible is this? Does this (completely untested) patch >>>> make any difference? >>>> >>> >>> Happened both times I booted 4.2-rc1 up, so I would say 100% so far. >>> I will test with your patch and report results. >>> >> >> Yes. This patch fixed the problem. > > That's great, but what changed recently to cause this problem to happen? > Any chance you can bisect to the problem commit? > :) Starting bisect now. Thankfully I built 4.1.0 in this tree which is good place to start. Let you know in a bit -- Shuah -- Shuah Khan Sr. Linux Kernel Developer Open Source Innovation Group Samsung Research America (Silicon Valley) shuahkh@osg.samsung.com | (970) 217-8978 -- 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/