Re: [GIT PULL] ACPI fixes for v5.18-rc5

[Rafael J. Wysocki]

On Thu, Apr 28, 2022 at 8:50 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Thu, Apr 28, 2022 at 8:30 AM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
> >
> >  - Make the ACPI processor driver avoid falling back to C3 type of
> >    C-states when C3 cannot be requested (Ville Syrjälä).
>
> Hmm.
>
> Doesn't this avoid C3 for _everybody_ rather than some conditional
> "when C3 cannot be requested"?

The bug was that if acpi_idle_bm_check() returned 1, it would "fall
back"  to the same state via safe_state_index.

> Of course, it looks like the 'has_lpi' state still potentially allows
> C3 even for busmastering sleeps. Maybe that is what you meant.

That too.

Thanks for pulling!

Rafael