From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Hoffmann Subject: Re: CPU_IDLE causes random reboots on custom 4430 Date: Tue, 25 Sep 2012 23:10:08 +0200 Message-ID: <50621DB0.9090607@christianhoffmann.info> References: <505CEEFD.1080507@gmail.com> <505DF146.6050100@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from [88.175.101.52] ([88.175.101.52]:42798 "EHLO christianhoffmann.info" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1757997Ab2IYVKh (ORCPT ); Tue, 25 Sep 2012 17:10:37 -0400 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Shilimkar, Santosh" Cc: Chris Hoffmann , linux-omap@vger.kernel.org On 09/23/2012 06:11 PM, Shilimkar, Santosh wrote: > On Sat, Sep 22, 2012 at 10:41 PM, Chris Hoffmann wrote: >> On 09/22/2012 07:45 AM, Shilimkar, Santosh wrote: >>> >>> On Sat, Sep 22, 2012 at 4:19 AM, Chris Hoffmann >>> wrote: >>>> >>>> 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. >>>> >>> On the same kernel, you should have support for the persistent log. You >>> might >>> want to check the output. That should give you pointers on what CPU was >>> doing before the freeze which resulted in reboot. >> >> >> Hi, >> >> I have some problems to provide logs. If I add -DDEBUG to cpuidle44xx.o the >> problem doesn't seem to occur. It could be that printk-ing alleviates the >> issue. >> >> Also the watchdog seems to shutdown the device rather than rebooting it (or >> it hangs?) and then I can't provide /proc/last_kmsg. >> >> How could I provide more info? >> > Check if you have "/sys/kernel/debug/persistent_trace" available on > your kernel. This generally helps whenever there are hangs, the last > call stack is stored on memory and on the reboot it can be cat'ed to > see if some useful information about hang is available. Hi Santosh, all, the p-android-omap-3.0 doesn't have the persistent_trace but I was able to backport it from 3.4 without major issues (only tricky part is that in p-android-3.4 there's no apparent user of that device in omapzoom kernel). The problem is now that the omap-watchdog doesn't kick the device to reboot but rather to shutdown, so I still have no trace. Soft-rebooting shows that I can get persistent_trace. Switching the persistent tracer to ecc=true does not help as it seems to overload the device completely when activating the tracing. Rgds, Chris