Re: [PATCH] drm/i915: disable LVDS downclock by default

From: Jesse Barnes
Date: Thu Jan 14 2010 - 17:06:16 EST


On Thu, 14 Jan 2010 23:25:57 +0200
Pekka Enberg <penberg@xxxxxxxxxxxxxx> wrote:

> Hi Jesse,
>
> On Thu, Jan 14, 2010 at 10:48 PM, Jesse Barnes
> <jbarnes@xxxxxxxxxxxxxxxx> wrote:
> > Many platform support this feature, and it can provide significant
> > power savings when the reduced refresh rate is low. ÂHowever, on
> > some platforms a secondary (reduced) timing is provided but not
> > actually supported by the hardware. ÂThis results in undesirable
> > flicker at runtime.
> >
> > So disable the feature by default, but allow users to opt-in to the
> > reduced clock behavior with a new module parameter, lvds_downclock,
> > that can be set to 1 to enable the feature.
> >
> > Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
> >
> > --
> >
> > Nick and Pekka, please try this out and reply with your Tested-by
> > (assuming it works, if not I'll fix it up).
>
> This gives me pretty much identical results as your original patch.
> That is, the "shakes" are gone but I still see the occasional "flash".
> Should I give Nick's patch a try to see if we're looking at the same
> issue or wait for your new patch?

Nick's patch should be the same, thanks for testing.

--
Jesse Barnes, Intel Open Source Technology Center
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