From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Hoffmann Subject: CPU_IDLE causes random reboots on custom 4430 Date: Sat, 22 Sep 2012 00:49:33 +0200 Message-ID: <505CEEFD.1080507@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-we0-f174.google.com ([74.125.82.174]:37534 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932852Ab2IUWti (ORCPT ); Fri, 21 Sep 2012 18:49:38 -0400 Received: by weyx8 with SMTP id x8so2231041wey.19 for ; Fri, 21 Sep 2012 15:49:37 -0700 (PDT) Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-omap@vger.kernel.org Hi, We're trying to get a custom 4430 board (aka. nook tablet with OMAP4430 ES2.3 HS TWL6030 ES2.1) working with p-android-omap-3.0 on android jelly bean. The board works quite well, but we experience random hangs and the watchdog kicks the board to reboot. The problem is that kmsg_last doesn't not show any useful information and the fiq debugger refuses to work when the device is locked up. We also enabled various kernel lock debugging configs to get more info ... in vain. Experimenting with it for a while (removing non-standard drivers like accel, charger, battery, etc) we found that removing CONFIG_CPU_IDLE or setting disallow_smp_idle in cpuidle44xx.c seems to cure the random lockups and make the board work fine (apart from the maybe obvious consequences that it doesn't go to deep sleep anymore). Further below a few sample infos from the board. We'd very much appreciate any further help on how to proceed to find the root cause and happy to provide any more info from sys, debug or omapconf tool. Rgds, Chris A dmesg from a normal boot: https://dl.dropbox.com/u/21820416/CPU_IDLE_CRASH/dmesg.log Kernel source: https://github.com/Kuzma30/kernel3NookTablet/tree/jellybean omapconf --cpuinfo https://dl.dropbox.com/u/21820416/CPU_IDLE_CRASH/omapconf.cpuinfo cat /sys/kernel/debug/clock/summary https://dl.dropbox.com/u/21820416/CPU_IDLE_CRASH/clock.summary ... what else can we provide to track this down?