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

From: Pekka Enberg
Date: Thu Jan 14 2010 - 16:26:08 EST


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.  However, on some
> platforms a secondary (reduced) timing is provided but not actually
> supported by the hardware.  This 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?

Pekka
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