From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758008Ab2D1ACh (ORCPT ); Fri, 27 Apr 2012 20:02:37 -0400 Received: from mail-iy0-f174.google.com ([209.85.210.174]:47908 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756824Ab2D1ACg (ORCPT ); Fri, 27 Apr 2012 20:02:36 -0400 Message-ID: <4F9B3398.9060701@lwfinger.net> Date: Fri, 27 Apr 2012 19:02:32 -0500 From: Larry Finger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120328 Thunderbird/11.0.1 MIME-Version: 1.0 To: Benjamin Herrenschmidt CC: Paul Mackerras , linuxppc-dev@lists.ozlabs.org, LKML Subject: Re: Regression in 32-bit ppc kernel References: <4F973026.3020103@lwfinger.net> <1335311621.15830.42.camel@pasglop> <4F976352.4060001@lwfinger.net> <1335327081.21961.28.camel@pasglop> <4F98117C.7080309@lwfinger.net> <1335390257.21961.53.camel@pasglop> <4F9ABD67.3060704@lwfinger.net> <1335565573.20866.7.camel@pasglop> In-Reply-To: <1335565573.20866.7.camel@pasglop> 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 On 04/27/2012 05:26 PM, Benjamin Herrenschmidt wrote: > On Fri, 2012-04-27 at 10:38 -0500, Larry Finger wrote: > >> Sorry, I was unable to find anything in debugfs to help me learn about interrupt >> mapping. The value of CONFIG_NR_IRQS is already 512. I have not tried reducing >> it to 128. The setting for CONFIG_SPARSE_IRQ was on, and changing it to off did >> not make any difference. >> >> I finished the bisection, which led to >> >> commit a79dd5ae5a8f49688d65b89a859f2b98a7ee5538 >> Author: Benjamin Herrenschmidt >> Date: Thu Dec 15 11:13:03 2011 +1100 >> >> tty/serial/pmac_zilog: Fix suspend& resume >> >> As this seemed to be an improbable result, I did the full test by checking out >> the previous commit (43ca5d3). That resulted in a "good" result. Then I used >> quilt to add commit a79dd5a as a patch and the fault returned. I then noticed >> that you said in the commit message that "I removed some code for handling >> unexpected interrupt which should never be hit...". It appears that my box does >> indeed hit such an unexpected interrupt. >> >> I could always get rid of the fault by disabling CONFIG_SERIAL_PMACZILOG, but I >> would like to fix the problem if possible. > > Right, it should be fixed. I need to understand where the unexpected > interrupt comes from. Can you tell me (or remind me) what specific > machine model you are using ? Are you putting the console on the serial > port ? It is a 15" Powerbook G4. I think they call it a Titanium. The console is not on a serial port. In fact, the reason that I did not think this patch was a problem is because the serial port does not appear to be connected to an external port. I was unaware that there was a serial port on the motherboard. There is a modem jack, but no 9 or 25-pin connectors that would indicate a standard serial port. There are two stack dumps with the same trace. I posted the first, but the second is preceded by the lines [