Re: [REGRESSION 4.17] Spurious wakeup / reboot with power button

[Takashi Iwai <tiwai@suse.de>]

On Thu, 05 Jul 2018 16:00:14 +0200,
Thomas H4nig wrote:
> 
> Am 05.07.2018 um 14:12 schrieb Takashi Iwai:
> > On Thu, 05 Jul 2018 12:41:03 +0200,
> > Rafael J. Wysocki wrote:
> >>
> >> On Thursday, July 5, 2018 11:50:11 AM CEST Takashi Iwai wrote:
> >>> On Thu, 05 Jul 2018 11:34:59 +0200,
> >>> Rafael J. Wysocki wrote:
> >>>>
> >>>> Hi,
> >>>>
> >>>> On Thu, Jul 5, 2018 at 9:05 AM, Takashi Iwai <tiwai@suse.de> wrote:
> >>>>> Hi,
> >>>>>
> >>>>> we've got a regression report since 4.17 about the behavior of
> >>>>> power-off with the power button.  When a machine is powered off with
> >>>>> the power button on desktop, it reboots after a few seconds instead of
> >>>>> power down.
> >>>>>
> >>>>> The manual power down via "systemctl poweroff" works fine, so it's
> >>>>> possibly some spurious wakeup by the power button action, and some
> >>>>> ACPI-related change is suspected.
> >>>>> The regression still remains in 4.18-rc3.
> >>>>
> >>>> There are only a few ACPI commits directly related to power management
> >>>> between 4.16 and 4.17 and none of them looks particularly suspicious.
> >>>
> >>> OK, interesting.
> >>>
> >>>> It looks like the power button state may not be cleared sufficiently
> >>>> after it's been pressed which is now visible for some reason.
> >>>
> >>> Hmm, where can such a state remain?  Since it happens after the
> >>> machine turned off, some (ACPI) wakeup bits?
> >>
> >> Basically, yes.
> >>
> >> It looks like a GPE may remain active which then triggers wakeup after
> >> shutdown.
> >>
> >> On a hunch, I'm wondering if reverting commit
> >>
> >> 18996f2db918 ACPICA: Events: Stop unconditionally clearing ACPI IRQs during suspend/resume
> >>
> >> (may not revert clearly, though) makes any difference.
> > 
> > OK, I'm building a 4.17.x test kernel with that revert, in OBS
> > home:tiwai:bsc1099930 repo.
> > 
> > Thomas, could you try later the kernel in
> >   http://download.opensuse.org/repositories/home:/tiwai:/bsc1099930/standard/
> > ?  It'll take an hour or so until the build finishes.
> 
> With your new built kernel
> 4.17.4-1.g6f23755-default
> 
> the power button works again, so the revert solved the problem

Thanks, that clarifies the cause.
Adding Erik and Lv to Cc.

I guess it's the side-effect by removing
	acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
in acpi_hw_disable_all_gpes().

This function is called from acpi_power_off_prepare(), and the machine
goes to power off without clearing the GPEs, hence it's woken up later
unexpectedly.


Takashi