[Intel-gfx] [PATCH 07/28] drm/i915: implement WaForceL3Serialization on VLV and IVB

[Jesse Barnes]

On Fri, 1 Mar 2013 23:43:25 +0200
Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:

> On Fri, Mar 01, 2013 at 01:14:10PM -0800, Jesse Barnes wrote:
> > References: https://bugs.freedesktop.org/show_bug.cgi?id=50250
> > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h |    3 +++
> >  drivers/gpu/drm/i915/intel_pm.c |    4 ++++
> >  2 files changed, 7 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 766518b..09b9072 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -3583,6 +3583,9 @@
> >  #define GEN7_L3SQCREG4				0xb034
> >  #define  L3SQ_URB_READ_CAM_MATCH_DISABLE	(1<<27)
> >  
> > +#define GEN7_L3SQCREG4				0xb034
> > +#define  L3SQ_URB_READ_CAM_MATCH_DISABLE	(1<<27)
> > +
> >  /* WaCatErrorRejectionIssue */
> >  #define GEN7_SQ_CHICKEN_MBCUNIT_CONFIG		0x9030
> >  #define  GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB	(1<<11)
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 61fee7f..0f1adc8 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -3830,6 +3830,10 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
> >  	I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
> >  		   ~L3SQ_URB_READ_CAM_MATCH_DISABLE);
> >  
> > +	/* WaForceL3Serialization */
> > +	I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
> > +		   ~L3SQ_URB_READ_CAM_MATCH_DISABLE);
> 
> I suspect doing it twice won't serialize things any further ;)
> 
> Actually it seems we're already clearing the bit twice. So this
> is the third one you're adding.
> 

Oh good I can drop this one then.

-- 
Jesse Barnes, Intel Open Source Technology Center