Re: power-off delay/hang due to commit 6d25be57 (mainline)

Sebastian Andrzej Siewior
2020-07-14T16:10:27Z

On 2020-07-14 17:53:15 [+0200], Rafael J. Wysocki wrote:
> > shows the pattern and we nailed it down that it comes from
> > thermal_get_temp().
>
> acpi_evaluate_integer() doesn't show up in the trace, though, AFAICS.

I deducted it. acpi_thermal_get_temperature() -> acpi_evaluate_integer()
and the dmesg showed
| ACPI: Invalid passive threshold
| thermal LNXTHERM:00: registered as thermal_zone0
| ACPI: Thermal Zone [TZ10] (17 C)
| thermal LNXTHERM:01: registered as thermal_zone1
| ACPI: Thermal Zone [TZ00] (28 C)

and overriding thermal.tzp to a higher value made the issue go away.
There is a complete dmesg
https://lore.kernel.org/lkml/87v9l65d2y.fsf@gmx.net/

> > I assumed acpi_ex_opcode_2A_0T_0R() since the other
> > candidate was acpi_ev_asynch_execute_gpe_method().
>
> Which probably is the case. Specifically
>
> acpi_ev_asynch_execute_gpe_method: Evaluate _L66
>
> is likely to cause the Notify() to be dispatched.

Okay. I hope Stephen replies later with a backtrace.

> > Stephen, the patch attached adds a WARN_ON() statement which will
> > produce a stack trace (4 or so). Could please run 'dmesg' after a while
> > and send it back. There should be a
> > "WARNING in drivers/acpi/acpica/evmisc.c"
> >
> > statement or something along the lines.
> >
> > Rafael, are you also interested in an ACPI dump?
>
> That might help a bit.
>
> So what probably happens is that poking at the TZ causes a GPE to
> trigger and a Notify() to be dispatched which then goes into the
> workqueue for execution.
>
> Now, I'm not sure what happens to those Notify() items, though. They
> each should cause a handler (in the thermal driver) to be executed,
> but does that happen?

Are you asking for a trace point in acpi_ev_notify_dispatch() to see
what it actually calls as in info->notify.global->handler /
handler_obj->notify.handler ?
There is no handler in the thermal driver or do I just not recognize it?

Sebastian