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

[Ville Syrjälä]

On Wed, May 11, 2016 at 08:44:45AM -0400, Steven Rostedt wrote:
> On Wed, 11 May 2016 15:21:16 +0300
> Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote:
> 
> > 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.
> > 
> 
> Can you look at the documentation in the kernel code at
> 
> Documentation/power/basic-pm-debugging.txt And follow the procedures
> for testing suspend to RAM (although it requires mostly running the
> same tests as for hibernation suspending).
> 
> You can also use the tool s2ram for this as well.
> 
> See Documentation/power/s2ram.txt
> 
> Perhaps this can give us a bit more light onto the problem.
> 
> Basically the above does partial suspend and resume, and can pinpoint
> problem areas down to a more select location.

All the pm_test modes work fine. The only difference between them was
that 'platform' required me to manually wake up the machine (hitting a
key was sufficient), whereas the others woke up without help.

pm_trace gave me
[    1.306633]   Magic number: 0:185:178
[    1.322880]   hash matches ../drivers/base/power/main.c:1070
[    1.339270] acpi device:0e: hash matches
[    1.355414]  platform: hash matches

which is the TRACE_SUSPEND in __device_suspend_noirq(), so no help
there.

I guess I could try to sprinkle more TRACE_RESUMEs around into some
early resume code. If anyone has good ideas where to put them it
might speed things up a bit.

-- 
Ville Syrjälä
Intel OTC