diff mbox

[2/2] drm/i915: Add thread stall DOP clock gating workaround on Broadwell.

Message ID 1393487971-739-2-git-send-email-kenneth@whitecape.org (mailing list archive)
State New, archived
Headers show

Commit Message

Kenneth Graunke Feb. 27, 2014, 7:59 a.m. UTC
Ben and I believe this will be necessary on production hardware.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
---
 drivers/gpu/drm/i915/i915_reg.h | 1 +
 drivers/gpu/drm/i915/intel_pm.c | 4 ++++
 2 files changed, 5 insertions(+)

Comments

Ville Syrjälä Feb. 27, 2014, 8:43 a.m. UTC | #1
On Wed, Feb 26, 2014 at 11:59:31PM -0800, Kenneth Graunke wrote:
> Ben and I believe this will be necessary on production hardware.
> 
> Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
> ---
>  drivers/gpu/drm/i915/i915_reg.h | 1 +
>  drivers/gpu/drm/i915/intel_pm.c | 4 ++++
>  2 files changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f36d5e0..ade1d71 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -5052,6 +5052,7 @@
>  
>  #define GEN8_ROW_CHICKEN		0xe4f0
>  #define   PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE	(1<<8)
> +#define   STALL_DOP_GATING_DISABLE		(1<<5)
>  
>  #define GEN7_ROW_CHICKEN2		0xe4f4
>  #define GEN7_ROW_CHICKEN2_GT2		0xf4f4
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index df8ad21..226591d 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4842,6 +4842,10 @@ static void gen8_init_clock_gating(struct drm_device *dev)
>  	I915_WRITE(GEN8_ROW_CHICKEN,
>  	           _MASKED_BIT_ENABLE(PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE));
>  
> +	/* WaDisableThreadStallDopClockGating:bdw */
> +	I915_WRITE(GEN8_ROW_CHICKEN,
> +		   _MASKED_BIT_ENABLE(STALL_DOP_GATING_DISABLE));

The spec and w/a database are a bit confused on this, but I get the
impression that you're correct. So:

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> +
>  	/*
>  	 * This GEN8_CENTROID_PIXEL_OPT_DIS W/A is only needed for
>  	 * pre-production hardware
> -- 
> 1.8.4.2
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Ville Syrjälä Feb. 27, 2014, 9:08 a.m. UTC | #2
On Thu, Feb 27, 2014 at 10:43:34AM +0200, Ville Syrjälä wrote:
> On Wed, Feb 26, 2014 at 11:59:31PM -0800, Kenneth Graunke wrote:
> > Ben and I believe this will be necessary on production hardware.
> > 
> > Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h | 1 +
> >  drivers/gpu/drm/i915/intel_pm.c | 4 ++++
> >  2 files changed, 5 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index f36d5e0..ade1d71 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -5052,6 +5052,7 @@
> >  
> >  #define GEN8_ROW_CHICKEN		0xe4f0
> >  #define   PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE	(1<<8)
> > +#define   STALL_DOP_GATING_DISABLE		(1<<5)
> >  
> >  #define GEN7_ROW_CHICKEN2		0xe4f4
> >  #define GEN7_ROW_CHICKEN2_GT2		0xf4f4
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index df8ad21..226591d 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -4842,6 +4842,10 @@ static void gen8_init_clock_gating(struct drm_device *dev)
> >  	I915_WRITE(GEN8_ROW_CHICKEN,
> >  	           _MASKED_BIT_ENABLE(PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE));
> >  
> > +	/* WaDisableThreadStallDopClockGating:bdw */
> > +	I915_WRITE(GEN8_ROW_CHICKEN,
> > +		   _MASKED_BIT_ENABLE(STALL_DOP_GATING_DISABLE));
> 
> The spec and w/a database are a bit confused on this, but I get the
> impression that you're correct. So:
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Actually I might have to take that back a bit. Looks more like it
shouldn't be needed for production hardware, but I'm guessing people
currently have hardware that needs it, so we should have it at least
for now.

> 
> > +
> >  	/*
> >  	 * This GEN8_CENTROID_PIXEL_OPT_DIS W/A is only needed for
> >  	 * pre-production hardware
> > -- 
> > 1.8.4.2
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Ville Syrjälä
> Intel OTC
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f36d5e0..ade1d71 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5052,6 +5052,7 @@ 
 
 #define GEN8_ROW_CHICKEN		0xe4f0
 #define   PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE	(1<<8)
+#define   STALL_DOP_GATING_DISABLE		(1<<5)
 
 #define GEN7_ROW_CHICKEN2		0xe4f4
 #define GEN7_ROW_CHICKEN2_GT2		0xf4f4
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index df8ad21..226591d 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4842,6 +4842,10 @@  static void gen8_init_clock_gating(struct drm_device *dev)
 	I915_WRITE(GEN8_ROW_CHICKEN,
 	           _MASKED_BIT_ENABLE(PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE));
 
+	/* WaDisableThreadStallDopClockGating:bdw */
+	I915_WRITE(GEN8_ROW_CHICKEN,
+		   _MASKED_BIT_ENABLE(STALL_DOP_GATING_DISABLE));
+
 	/*
 	 * This GEN8_CENTROID_PIXEL_OPT_DIS W/A is only needed for
 	 * pre-production hardware