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

Rafael J. Wysocki
2020-07-14T13:55:13Z

On Tue, Jul 14, 2020 at 3:44 PM Sebastian Andrzej Siewior
<bigeasy@linutronix.de> wrote:>
> On 2020-06-24 23:49:52 [+0200], Stephen Berman wrote:
>
> Let me summarize the thread here:
>
> On Stephen's system, ACPI informs the thermal zone driver to poll the
> temperature every second and the driver does so.
> The driver queries the temperature by invoking acpi_evaluate_integer()
> which invokes (at some point) acpi_ev_queue_notify_request().

Well, I don't quite see how acpi_ev_queue_notify_request() can be
invoked from the acpi_evaluate_integer() code path.

Do you have a call trace showing that?

> This then invokes acpi_os_execute_deferred() via
> queue_work_on(, kacpi_notify_wq, )
>
> acpi_os_execute_deferred() invokes acpi_ev_notify_dispatch() and this is
> no longer synchronised with the initial acpi_evaluate_integer() request.

That indeed would be the case, but I first need to understand what's
going on with the acpi_evaluate_integer() causing a Notify () to be
queued up.

Cheers!