Kernel panic when unpluggin AC adaptor

[David DEMELIER]

2010/5/12 Giovanni Trematerra <giovanni.trematerra at gmail.com>:
> On Fri, May 7, 2010 at 8:33 PM, Demelier David <demelier.david at gmail.com> wrote:
>> Le Vendredi 07 mai 2010 à 18:22 +0200, Giovanni Trematerra a écrit :
>>> On Fri, May 7, 2010 at 2:08 PM, Demelier David <demelier.david at gmail.com> wrote:
>>> > Hi,
>>> >        I noticed that pluggin the AC adaptor when I boot without it does not
>>> >        panic. It only panic when removing it.
>>> >
>>> >        Maybe that could help ?
>>> >
>>>
>>> Good to know. The problem lies somewhere when performance state change.
>>> In your case it happens when you remove AC adaptor. Let's hope someone on
>>> acpi@ ml comes up with a good idea.
>>>
>>
>> Okay so for the moment no change, I'll wait for someone with an idea
>> that could solve my problem. For me because the panic only happens when
>> changing profile from ac plugged -> ac unplugged (and not the reverse) I
>> would think it's a cpu related acpi issue.
>>
>
> I looked deeper and it seems to me that when you unplug the AC
> adapter, acpi_cpu_notify calls acpi_cpu_cx_cst that try to allocate a
> new cx_ptr->p_lvlx  via acpi_PkgGas.
> If acpi_PkgGas set cx_ptr->p_lvlx to NULL for any reasons you'll have
> the panic that you reported.
> A solution would be to set acpi_cpu_hook to NULL so acpi_cpu_idle won't call it.
> I need some time to have a patch because of the possible race between
> acpi_cpu_notify and
> acpi_cpu_idle during set acpi_cpu_hook to NULL.
> if you have time and want panic your system you could try the attached
> patch, just to be
> sure that we catch it.
>

Hi, it paniced today ! I don't know why it randomly panic but it did,
the backtrace didn't change. There is a picture about the panic :

http://img541.imageshack.us/img541/2773/dsc00388xa.jpg

Cheers.

-- 
Demelier David