Re: [PATCH 08/28] drm/i915: Fix IVB GT2 WaDisableDopClockGating and WaDisablePSDDualDispatchEnable

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

On Tue, Jan 28, 2014 at 10:06:05AM -0200, Rodrigo Vivi wrote:
> I agree that spec is strange, but following the spec correctly result
> for this and next patch would be only this:
> 
> if (IS_IVB_GT1(dev))
>   I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
>     _MASKED_BIT_ENABLE(GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
> - else
>   I915_WRITE(GEN7_HALF_SLICE_CHICKEN1_GT2,
>     _MASKED_BIT_ENABLE(GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
>  }

That would match what the w/a database says. But bspec says otherwise.

But anyway Chris confirmed on his GT1 that GEN7_HALF_SLICE_CHICKEN1_GT2
doesn't exist there, so I think these patches are correct.

> 
> On Fri, Jan 24, 2014 at 3:58 PM, Ville Syrjälä
> <ville.syrjala@linux.intel.com> wrote:
> > On Fri, Jan 24, 2014 at 03:32:08PM -0200, Rodrigo Vivi wrote:
> >> Your patch itself makes sense, but the registers values there are at i915_reg.h
> >> differs from what I see at BSpec:
> >>
> >> #define GEN7_ROW_CHICKEN2               0xe4f4
> >> #define GEN7_ROW_CHICKEN2_GT2           0xf4f4
> >>
> >> against
> >> Address: 0E4F0h
> >> Valid Projects: [DevIVB, EXCLUDE(DevIVB:GT2)]
> >> Address: 0F4F0h
> >> Valid Projects: [DevIVB:GT2]
> >
> > ROW_CHICKEN vs. ROW_CHICKEN2
> >
> >>
> >> Also, I couldn't see the wa description at wa_database...
> >> description was empty for me..
> >
> > Which one? WaDisableDopClockGating? It's not in the list for IVB,
> > so in order to see it you need to pick another platform which
> > includes this w/a.
> >
> >>
> >> On Wed, Jan 22, 2014 at 5:32 PM,  <ville.syrjala@linux.intel.com> wrote:
> >> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >> >
> >> > IVB GT2 has two registers for these things, and both must be written.
> >> >
> >> > To add a bit more confusion both Bspec and the W/A database state that
> >> > WaDisablePSDDualDispatchEnable is only needed for IVB GT1, but the W/A
> >> > database also says to write even the second GT2 only register. So I
> >> > don't really know what the right thing here is.
> >> >
> >> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >> > ---
> >> >  drivers/gpu/drm/i915/intel_pm.c | 13 ++++++++++---
> >> >  1 file changed, 10 insertions(+), 3 deletions(-)
> >> >
> >> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> >> > index 6a1d98a..b268a55 100644
> >> > --- a/drivers/gpu/drm/i915/intel_pm.c
> >> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> >> > @@ -4828,9 +4828,13 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
> >> >         if (IS_IVB_GT1(dev))
> >> >                 I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
> >> >                            _MASKED_BIT_ENABLE(GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
> >> > -       else
> >> > +       else {
> >> > +               /* must write both registers */
> >> > +               I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
> >> > +                          _MASKED_BIT_ENABLE(GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
> >> >                 I915_WRITE(GEN7_HALF_SLICE_CHICKEN1_GT2,
> >> >                            _MASKED_BIT_ENABLE(GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
> >> > +       }
> >> >
> >> >         /* Apply the WaDisableRHWOOptimizationForRenderHang:ivb workaround. */
> >> >         I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
> >> > @@ -4846,10 +4850,13 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
> >> >         if (IS_IVB_GT1(dev))
> >> >                 I915_WRITE(GEN7_ROW_CHICKEN2,
> >> >                            _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
> >> > -       else
> >> > +       else {
> >> > +               /* must write both registers */
> >> > +               I915_WRITE(GEN7_ROW_CHICKEN2,
> >> > +                          _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
> >> >                 I915_WRITE(GEN7_ROW_CHICKEN2_GT2,
> >> >                            _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
> >> > -
> >> > +       }
> >> >
> >> >         /* WaForceL3Serialization:ivb */
> >> >         I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
> >> > --
> >> > 1.8.3.2
> >> >
> >> > _______________________________________________
> >> > Intel-gfx mailing list
> >> > Intel-gfx@lists.freedesktop.org
> >> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >>
> >>
> >>
> >> --
> >> Rodrigo Vivi
> >> Blog: http://blog.vivi.eng.br
> >
> > --
> > Ville Syrjälä
> > Intel OTC
> 
> 
> 
> -- 
> Rodrigo Vivi
> Blog: http://blog.vivi.eng.br

-- 
Ville Syrjälä
Intel OTC