[Intel-gfx] [PATCH] drm/i915: add render standby support

[Andrew Lutomirski]

On Thu, Oct 8, 2009 at 12:46 PM, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> On Thu, 8 Oct 2009 12:04:32 +0200
> Erik Andrén <erik.andren at gmail.com> wrote:
>
>> 2009/10/7 Jesse Barnes <jbarnes at virtuousgeek.org>:
>> > Render standy allows the GPU to power down the render unit when
>> > idle. In order for this to work, it needs a page of graphics memory
>> > to save state.  This patch allocates that page and enables the
>> > feature on supported chipsets.
>> >
>> > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
>> > ---
>>
>> Do you have any figures on how much power this saves?
>
> I haven't done any measurements yet.  I had to do this as part of some
> other work and figured I'd get it out there after some light testing.

For fun, I compiled and ran it on my laptop.  I didn't get any
noticeable savings over 2.6.32-rc3 (with a hack added in to
force-enable render_reclock_avail and lvds_downclock_avail on my
GM45), but nothing went wrong either.

While I'm here, silly question: what's supposed to enable lvds_downclock_avail?

--Andy

>
> --
> Jesse Barnes, Intel Open Source Technology Center
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>