Re: [PATCH v4 5/6] drm/i915/vlv:Implement the WA 'WaDisable_RenderCache_OperationalFlush'

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Apr 04, 2014 at 04:24:05PM +0100, Chris Wilson wrote:
> On Fri, Apr 04, 2014 at 05:14:38PM +0530, sourab.gupta@intel.com wrote:
> > From: Akash Goel <akash.goel@intel.com>
> > 
> > On Gen4+ platforms (except BDW), Render Cache Operational flush
> > cannot be enabled.
> > This WA is apparently required for all Gen4+ platforms,except BDW.
> > In BDW, the bit has been repurposed otherwise.
> > This has been tested only on vlv.
> > 
> > v2: Corrected the code regarding the wrong usage of
> > MASKED_BIT_DISABLE (Chris)
> > 
> > v3: Enhancing the scope of WA to Gen4+ platforms except BDW (Ville)
> > 
> > v4: Adding WA for g4x, crestline, broadwater (Ville)
> > 
> > Signed-off-by: Akash Goel <akash.goel@intel.com>
> > Signed-off-by: Sourab Gupta <sourab.gupta@intel.com>
> > Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Note that we now have a redundant CM0_RC_OP_FLUSH_DISABLE (which fails
> the name test anyway).

That's the correct name for the bit on gen3 AFAICS. Might be interesting
to try to flip it on gen3 and see if we get moar fps :P

> I'm also not a fan of
> enable(RC_OP_FLUSH_ENABLE)/disable(RC_OP_FLUSH_ENABLE) either, but as
> far as the content goes,
> 
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> 
> Sadly, it didn't appear to fix any bugs.
> -Chris
> 
> -- 
> Chris Wilson, Intel Open Source Technology Centre

-- 
Ville Syrjälä
Intel OTC