[Intel-gfx] [PATCH] drm/i915/cnl: WaRsUseTimeoutMode

[Chris Wilson]

Quoting Chris Wilson (2017-10-16 20:54:59)
> Quoting Rodrigo Vivi (2017-10-16 19:16:58)
> > On Mon, Oct 16, 2017 at 12:07:23PM +0000, David Weinehall wrote:
> > > On Tue, Aug 22, 2017 at 04:58:28PM -0700, Rodrigo Vivi wrote:
> > > > Apparently RC6 residency is lower than expected
> > > > with EI mode for most of the cases on CNL A0, B0 and C0.
> > > > 
> > > > This Wa doesn't solve our lower residency, but I
> > > > believe it is better to have it since EI is not
> > > > expected to work by HW engineers anyways.
> 
> Aside, this has nothing* to do with rc6; this is changing the decision to
> up/down clock to a metric that is out of kilter with the code.
> 
> *Ok, you can make an indirect claim about race-to-idle and the rc6
> hysteresis.

Egg on face; wrong register, wrong EI/TO decision.
-Chris