From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id AF532B6FCA for ; Sat, 28 Apr 2012 08:26:23 +1000 (EST) Message-ID: <1335565573.20866.7.camel@pasglop> Subject: Re: Regression in 32-bit ppc kernel From: Benjamin Herrenschmidt To: Larry Finger Date: Sat, 28 Apr 2012 08:26:13 +1000 In-Reply-To: <4F9ABD67.3060704@lwfinger.net> 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> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras , LKML List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 ? Cheers, Ben.