proposal: set default lid state to S3, performance/economy Cx states to Cmax

[John Baldwin]

On Monday, May 05, 2014 12:55:29 pm Adrian Chadd wrote:
> On 5 May 2014 08:09, John Baldwin <jhb at freebsd.org> wrote:
> > On Sunday, May 04, 2014 4:27:38 am Adrian Chadd wrote:
> >> Hi,
> >>
> >> I'd like to propose flipping a few things:
> >>
> >> * Flipping the default lid state to S3. I think ACPI suspend/resume
> >> seems to work well enough these days and I've not met anyone lately
> >> who expects the default from their laptop to be "stay awake with the
> >> lid shut."
> >> * Save chip bugs that we should add workarounds for, we should be OK
> >> to enter lower sleep states when idling. Flipping this may expose some
> >> further crazy driver, platform or timer bugs, but they again likely
> >> should be fixed.
> >>
> >> what do people think?
> >
> > I think the lid switch thing is premature.  Even on my X220 I use a devd
> > hook to enable it only when i915drm is loaded as resume doesn't work until
> > that is done.
> >
> > I think the Cmax thing OTOH is probably more appropriate.  We have several
> > things place that should "mostly" DTRT for picking the correct timers to
> > use.  The one case I know of recently were some somewhat older systems where
> > the HPET wasn't reliable, but the system chose to use HPET instead of LAPIC
> > becuase the LAPIC was known to stop during C1E, etc.  In this case the user
> > just stuck with plain old C1 and forced the LAPIC timer which worked fine.
> > However, it is hard to identify those cases.  On modern systems I would
> > expect the LAPIC to work just fine, so this problem will become less and
> > less important as time goes on.
> 
> right. I'd rather we start finding more of these sooner rather than later. :-)

The user in question found this on 9-stable with the existing defaults as the
HPET was just plain broken on their system and that was unrelated to Cx states.
(Rather, Cx states were only involved because worries about them are why the
system chose to use HPET.  Had Cx states been enabled by default, they would
have had to disable those as well in addition to forcing LAPIC instead of
HPET.)

-- 
John Baldwin