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

[Chris Wilson]

Quoting Rodrigo Vivi (2017-10-17 00:32:54)
> On Mon, Oct 16, 2017 at 07:58:25PM +0000, Chris Wilson wrote:
> > 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.
> 
> I didn't follow, sorry.

Egg on face == my mistake, I took this was changing between Evaluation
Interval and Timeout for the RPS metrics. I had always associated rc6
with the timeout method.
-Chris