[Intel-gfx] [PATCH] drm/i915: Display WA #1185 WaDisableDARBFClkGating:cnl, glk

[Chris Wilson]

Quoting Rodrigo Vivi (2017-11-09 17:58:52)
> On Thu, Nov 09, 2017 at 01:45:04PM +0000, Ville Syrjälä wrote:
> > On Wed, Nov 08, 2017 at 03:30:16PM -0800, Rodrigo Vivi wrote:
> > > PM Rsp is not sent when plane is turned off at around the
> > > time that a PM fill Req is received by display
> > 
> > Do we know what the impact of this is? The HSD just seems to say
> > "Detection method: Hang" which isn't partciluarly helpful.
> > 
> > To me this smells vaguely of WaRsPkgCStateDisplayPMReq:hsw which
> > will cause a system hang if we don't do it early enough. Do we have
> > similar concerns here?
> 
> Well, I do have a bad display hang here and this patch didn't help...
> 
> > (and if so please look at commit f72b84c677d6
> > ("drm/i915: Move init_clock_gating() back to where it was"))
> 
> oh cool! thanks I will take a look on this...
> 
> > 
> > Maybe we should start a new init_clock_gating/init_workarounds thing
> > just for the display, and add all new stuff there? And then we can
> > start moving the old display w/as etc. there as well.
> 
> Maybe this is a work for that series that Oscar is working on?

It is something we all need input on to make sure the lessons learnt,
are.
-Chris