Re: S3 resume regression [1cf4f629d9d2 ("cpu/hotplug: Move online calls to hotplugged cpu")]

["Rafael J. Wysocki" <rafael.j.wysocki@intel.com>]

On 5/11/2016 2:21 PM, Ville Syrjälä wrote:
> On Wed, May 11, 2016 at 02:11:29PM +0200, Sebastian Andrzej Siewior wrote:
>> On 05/11/2016 12:19 PM, Ville Syrjälä wrote:
>>> Hi,
>> Hi,
>>
>>> I have a Lenovo Ideapad S10-3t machine here (Atom N450, 1 core, 2 HT)
>>> which fails to resume from S3 on 4.6-rc releases. I bisected it down to
>>>
>>> commit 1cf4f629d9d246519a1e76c021806f2a51ddba4d
>>> Author: Thomas Gleixner <tglx@linutronix.de>
>>> Date:   Fri Feb 26 18:43:39 2016 +0000
>>>
>>>      cpu/hotplug: Move online calls to hotplugged cpu
>>>
>>> Unfortunately that won't revert cleanly, and neither does the merge
>>> commit, so I was unable to see if that is the only problematic commit
>>> in 4.6.
>>>
>>> Any ideas?
>> do you have a backtrace or anything or is it just not working and you
>> end up with a blank screen?
> Yeah can't get anything from the machine at that point. netconsole
> didn't help either, and no serial on this machine. And IIRC I've
> tried ramoops on this thing in the past but unfortunately the memory
> got cleared on reboot.
>

Please try

# echo processors > /sys/power/pm_test

and then suspend (it should simulate a suspend, wait for approx. 5 sec 
and then resume, see
Documentation/power/basic_pm_debugging.txt for details).  See if that 
works or if you can get any
traces etc.

Thanks,
Rafael