[Intel-gfx] [PATCH] drm/i915/crt: Only support DPMS On/Off with the PCH registers

Keith Packard keithp at keithp.com
Tue Apr 10 19:30:46 CEST 2012

<#part sign=pgpmime>
On Tue, 10 Apr 2012 09:20:38 -0400, Adam Jackson <ajax at redhat.com> wrote:
> On 4/10/12 4:35 AM, Chris Wilson wrote:
> > As part of the PCH split, the ability to control CRT standby/suspend
> > states was defeatured; the bits are now marked reserved and apparently
> > have no effect.
> Are the intermediate states even tested?  I have vague memories of them 
> not working.  I'd be just as happy to see them aliased to Off.

It's worse than that -- iirc, there were patent issues with the
intermediate states which caused them to be removed from some newer
display signaling standards...

As far as I know, only CRTs could usefully use them anyways.

keith.packard at intel.com

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