Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752639AbdCBMlX (ORCPT ); Thu, 2 Mar 2017 07:41:23 -0500 Received: from mail-ot0-f179.google.com ([74.125.82.179]:36663 "EHLO mail-ot0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752599AbdCBMlR (ORCPT ); Thu, 2 Mar 2017 07:41:17 -0500 Subject: Re: Regression in 4.11 - PowerPC crashes on boot, bisected to commit 5657933dbb6e To: Bart Van Assche , "regressions@leemhuis.info" , "benh@kernel.crashing.org" References: <5bc9c08f-58aa-ef26-8891-4837e2d4184b@lwfinger.net> <1488431644.2870.64.camel@kernel.crashing.org> <1488432118.3505.4.camel@sandisk.com> Cc: "linux-kernel@vger.kernel.org" From: Larry Finger Message-ID: Date: Thu, 2 Mar 2017 06:40:40 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <1488432118.3505.4.camel@sandisk.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1655 Lines: 34 On 03/01/2017 11:22 PM, Bart Van Assche wrote: > On Thu, 2017-03-02 at 16:14 +1100, Benjamin Herrenschmidt wrote: >> On Wed, 2017-03-01 at 21:26 -0600, Larry Finger wrote: >>> My Powerbook G4 Aluminum generates a fatal splat early in the boot process, just >>> after identifying the driver for the disk. Unfortunately, it turns off almost >>> immediately, thus I cannot report the message. After this bug has been >>> triggered, the system clock has been reset to Dec. 31, 1969. I assume this is a >>> side effect of an uncontrolled DMA operation. >>> >>> This problem has been bisected to commit 5657933dbb6e ("treewide: Move dma_ops >>> from struct dev_archdata into struct device"). >> >> Side effect of a crash during boot... the PMU gets upset when we crash while >> there's a request in flight, that's probably what is happening. >> >> As to why that commit is broken, I don't have time to look into it right now, >> maybe next week of nobody beats me to it. > > Hello Ben, > > Thanks. I will try to reproduce what has been reported with qemu-ppc on Friday to > double check that it's really commit 5657933dbb6e that is causing this. I reread it > but couldn't find any reason why it works on x86-64 but not on powerpc. BTW, the > following patch is needed on at least s390 but probably also on powerpc to restore > InfiniBand support: http://marc.info/?l=linux-rdma&m=148823342415501&w=2. This is > why I asked for the kernel config. I am very confident of the bisection. A kernel built from commit 5299709, which is just before 5657933, boots correctly. As you have probably seen, my configuration does not include InfiniBand support. Larry