Thomas,
On Thursday, 20 September 2007 23:53, Thomas Gleixner wrote:
> Rafael,
>
> On Thu, 2007-09-20 at 23:45 +0200, Rafael J. Wysocki wrote:
> > > We disable everything in device_suspend()
> >
> > No, we don't. sysdevs are _not_ suspended in device_suspend().
> > They are suspended in device_power_down(), which is called
> > _after_ disable_nonboot_cpus() (from swsusp_suspend()).
> >
> > > including timekeeping,
> >
> > No, the timekeeping is suspended in device_power_down() (or at least it
> > should
> > be).
>
> Damn, you are right. Reading through 30 different logs confused me.
>
> > > enable_nonboot_cpus();
> >
> > Actually, we can't do this here, because of ACPI and some interrupt handling
> > related problems. Unfortunately, platform_finish() needs to go _after_
> > enable_nonboot_cpus() and device_resume() needs to go after
> > platform_finish().
> > Analogously, disable_nonboot_cpus() has to go after platform_prepare().
> >
> > Otherwise, some systems will break.
>
> Well, I don't buy this one. The system would break in the same way, when
> I take CPU#1 offline before I initiate the suspend.
>
> > > and non-surprisingly the "my VAIO needs help from keyboard" problem went
> > > away immediately. See patch below. (on top of rc7-hrt1, -mm1 does not
> > > work at all on my VAIO due to some yet not identified wreckage)
> >
> > Hm, I really don't know why it helps, but that's not because of the
> > timekeeping
> > suspend, IMO.
>
> It is related. We rely on some subtle thing which is not up when we
> resume the non boot cpu.
>
> > > I did not yet look into the suspend to ram code, but I guess that there
> > > is an equivalent problem.
> >
> > Yes, the code ordering is the same, but it's not totally wrong, IMHO.
> >
> > > But I have no idea why this affects Andrews jinxed VAIO (UP machine),
> > > though I suspect that we have more timekeeping/timer depending code
> > > somewhere waiting to bite us.
> >
> > That's possible.
> >
> > > Also I still need to debug why the HIBERNATION_TEST code path (which has
> > > a msleep(5000) in it) does not fail,
> >
> > See above. :-)
>
> Yes. It makes sense. When I change the TEST code path to:
>
> - printk("swsusp debug: Waiting for 5 seconds.\n");
> - msleep(5000);
> + printk("swsusp debug: before swsusp_suspend\n");
> + error = swsusp_suspend();
>
> then I have the same effect as I get from real hibernation. And we
> actually shut down time keeping somewhere in that code path.
>
> ACPI: PCI interrupt for device 0000:00:1b.0 disabled
> swsusp debug: before swsusp_suspend
> Suspend timekeeping
> swsusp: critical section:
> swsusp: Need to copy 112429 pages
> swsusp: Normal pages needed: 35399 + 1024 + 40, available pages: 193876
> swsusp: critical section: done (112429 pages copied)
> Intel machine check architecture supported.
> Intel machine check reporting enabled on CPU#0.
> Resume timekeeping
> ACPI: PCI Interrupt 0000:00:02.0[A] -> GSI 16 (level, low) -> IRQ 16
> -> works fine
>
> This is with my patch applied. Without that I get:
>
> CPU1 is down
> swsusp debug: before swsusp_suspend
> Suspend timekeeping
> swsusp: critical section:
> swsusp: Need to copy 112429 pages
> swsusp: Normal pages needed: 35399 + 1024 + 40, available pages: 193876
> swsusp: critical section: done (112429 pages copied)
> Intel machine check architecture supported.
> Intel machine check reporting enabled on CPU#0.
> Resume timekeeping
> Enabling non-boot CPUs
> --> Waits for ever until a key is pressed
Can you please run one more test?
Namely, without your debugging code in disk.c, please try
# echo shutdown > /sys/power/disk
# echo disk > /sys/power/state
Greetings,
Rafael
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