diff mbox

[08/12] drm/i915: Make sure PND deadline mode is enabled on VLV/CHV

Message ID 1423574909-1074-9-git-send-email-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ville Syrjälä Feb. 10, 2015, 1:28 p.m. UTC 
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Poke at the CBR1_VLV register during init_clock_gating to make sure the
PND deadline scheme is used.

The hardware has two modes of operation wrt. watermarks:

1) PND deadline mode:
 - memory request deadline is calculated from actual FIFO level * DDL
 - WM1 watermark values are unused (AFAIK)
 - WM watermark level defines when to start fetching data from memory
   (assuming trickle feed is not used)

2) backup mode
 - deadline is based on FIFO status, DDL is unused
 - FIFO split into three regions with WM and WM1 watermarks, each
   part specifying a different FIFO status

We want to use the PND deadline mode, so let's make sure the chicken
bit is in the correct position on init.

Also take the opportunity to refactor the shared code between VLV and
CHV to a shared function.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h |  3 +++
 drivers/gpu/drm/i915/intel_pm.c | 19 +++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

Comments

Jesse Barnes Feb. 27, 2015, 8:38 p.m. UTC | #1 
On 02/10/2015 05:28 AM, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Poke at the CBR1_VLV register during init_clock_gating to make sure the
> PND deadline scheme is used.
> 
> The hardware has two modes of operation wrt. watermarks:
> 
> 1) PND deadline mode:
>  - memory request deadline is calculated from actual FIFO level * DDL
>  - WM1 watermark values are unused (AFAIK)
>  - WM watermark level defines when to start fetching data from memory
>    (assuming trickle feed is not used)
> 
> 2) backup mode
>  - deadline is based on FIFO status, DDL is unused
>  - FIFO split into three regions with WM and WM1 watermarks, each
>    part specifying a different FIFO status
> 
> We want to use the PND deadline mode, so let's make sure the chicken
> bit is in the correct position on init.
> 
> Also take the opportunity to refactor the shared code between VLV and
> CHV to a shared function.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h |  3 +++
>  drivers/gpu/drm/i915/intel_pm.c | 19 +++++++++++++------
>  2 files changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 433d7e7..5d377df 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4177,6 +4177,9 @@ enum skl_disp_power_wells {
>  #define DDL_PRECISION_LOW		(0<<7)
>  #define DRAIN_LATENCY_MASK		0x7f
>  
> +#define CBR1_VLV			(VLV_DISPLAY_BASE + 0x70400)
> +#define  CBR_PND_DEADLINE_DISABLE	(1<<31)
> +
>  /* FIFO watermark sizes etc */
>  #define G4X_FIFO_LINE_SIZE	64
>  #define I915_FIFO_LINE_SIZE	64
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index e53038e..c021e92 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -6197,11 +6197,22 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
>  	gen6_check_mch_setup(dev);
>  }
>  
> +static void vlv_init_display_clock_gating(struct drm_i915_private *dev_priv)
> +{
> +	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
> +
> +	/*
> +	 * Disable trickle feed and enable pnd deadline calculation
> +	 */
> +	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
> +	I915_WRITE(CBR1_VLV, 0);
> +}
> +
>  static void valleyview_init_clock_gating(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> -	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
> +	vlv_init_display_clock_gating(dev_priv);
>  
>  	/* WaDisableEarlyCull:vlv */
>  	I915_WRITE(_3D_CHICKEN3,
> @@ -6249,8 +6260,6 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
>  	I915_WRITE(GEN7_UCGCTL4,
>  		   I915_READ(GEN7_UCGCTL4) | GEN7_L3BANK2X_CLOCK_GATE_DISABLE);
>  
> -	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
> -
>  	/*
>  	 * BSpec says this must be set, even though
>  	 * WaDisable4x2SubspanOptimization isn't listed for VLV.
> @@ -6287,9 +6296,7 @@ static void cherryview_init_clock_gating(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> -	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
> -
> -	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
> +	vlv_init_display_clock_gating(dev_priv);
>  
>  	/* WaVSRefCountFullforceMissDisable:chv */
>  	/* WaDSRefCountFullforceMissDisable:chv */
> 

Is the deadline mode preference documented somewhere?  Do we need
another bspec bug filed?

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Ville Syrjälä Feb. 27, 2015, 8:48 p.m. UTC | #2 
On Fri, Feb 27, 2015 at 12:38:44PM -0800, Jesse Barnes wrote:
> On 02/10/2015 05:28 AM, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Poke at the CBR1_VLV register during init_clock_gating to make sure the
> > PND deadline scheme is used.
> > 
> > The hardware has two modes of operation wrt. watermarks:
> > 
> > 1) PND deadline mode:
> >  - memory request deadline is calculated from actual FIFO level * DDL
> >  - WM1 watermark values are unused (AFAIK)
> >  - WM watermark level defines when to start fetching data from memory
> >    (assuming trickle feed is not used)
> > 
> > 2) backup mode
> >  - deadline is based on FIFO status, DDL is unused
> >  - FIFO split into three regions with WM and WM1 watermarks, each
> >    part specifying a different FIFO status
> > 
> > We want to use the PND deadline mode, so let's make sure the chicken
> > bit is in the correct position on init.
> > 
> > Also take the opportunity to refactor the shared code between VLV and
> > CHV to a shared function.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h |  3 +++
> >  drivers/gpu/drm/i915/intel_pm.c | 19 +++++++++++++------
> >  2 files changed, 16 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 433d7e7..5d377df 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -4177,6 +4177,9 @@ enum skl_disp_power_wells {
> >  #define DDL_PRECISION_LOW		(0<<7)
> >  #define DRAIN_LATENCY_MASK		0x7f
> >  
> > +#define CBR1_VLV			(VLV_DISPLAY_BASE + 0x70400)
> > +#define  CBR_PND_DEADLINE_DISABLE	(1<<31)
> > +
> >  /* FIFO watermark sizes etc */
> >  #define G4X_FIFO_LINE_SIZE	64
> >  #define I915_FIFO_LINE_SIZE	64
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index e53038e..c021e92 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -6197,11 +6197,22 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
> >  	gen6_check_mch_setup(dev);
> >  }
> >  
> > +static void vlv_init_display_clock_gating(struct drm_i915_private *dev_priv)
> > +{
> > +	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
> > +
> > +	/*
> > +	 * Disable trickle feed and enable pnd deadline calculation
> > +	 */
> > +	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
> > +	I915_WRITE(CBR1_VLV, 0);
> > +}
> > +
> >  static void valleyview_init_clock_gating(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> >  
> > -	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
> > +	vlv_init_display_clock_gating(dev_priv);
> >  
> >  	/* WaDisableEarlyCull:vlv */
> >  	I915_WRITE(_3D_CHICKEN3,
> > @@ -6249,8 +6260,6 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
> >  	I915_WRITE(GEN7_UCGCTL4,
> >  		   I915_READ(GEN7_UCGCTL4) | GEN7_L3BANK2X_CLOCK_GATE_DISABLE);
> >  
> > -	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
> > -
> >  	/*
> >  	 * BSpec says this must be set, even though
> >  	 * WaDisable4x2SubspanOptimization isn't listed for VLV.
> > @@ -6287,9 +6296,7 @@ static void cherryview_init_clock_gating(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> >  
> > -	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
> > -
> > -	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
> > +	vlv_init_display_clock_gating(dev_priv);
> >  
> >  	/* WaVSRefCountFullforceMissDisable:chv */
> >  	/* WaDSRefCountFullforceMissDisable:chv */
> > 
> 
> Is the deadline mode preference documented somewhere?  Do we need
> another bspec bug filed?

VLV display cluster HAS had a fairly good description. We can at least
hope it works well enough on VLV. Sadly it doesn't actually work the
way you'd expect on CHV, but that's a whole other story.

> 
> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 433d7e7..5d377df 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4177,6 +4177,9 @@  enum skl_disp_power_wells {
 #define DDL_PRECISION_LOW		(0<<7)
 #define DRAIN_LATENCY_MASK		0x7f
 
+#define CBR1_VLV			(VLV_DISPLAY_BASE + 0x70400)
+#define  CBR_PND_DEADLINE_DISABLE	(1<<31)
+
 /* FIFO watermark sizes etc */
 #define G4X_FIFO_LINE_SIZE	64
 #define I915_FIFO_LINE_SIZE	64
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index e53038e..c021e92 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6197,11 +6197,22 @@  static void ivybridge_init_clock_gating(struct drm_device *dev)
 	gen6_check_mch_setup(dev);
 }
 
+static void vlv_init_display_clock_gating(struct drm_i915_private *dev_priv)
+{
+	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
+
+	/*
+	 * Disable trickle feed and enable pnd deadline calculation
+	 */
+	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
+	I915_WRITE(CBR1_VLV, 0);
+}
+
 static void valleyview_init_clock_gating(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
+	vlv_init_display_clock_gating(dev_priv);
 
 	/* WaDisableEarlyCull:vlv */
 	I915_WRITE(_3D_CHICKEN3,
@@ -6249,8 +6260,6 @@  static void valleyview_init_clock_gating(struct drm_device *dev)
 	I915_WRITE(GEN7_UCGCTL4,
 		   I915_READ(GEN7_UCGCTL4) | GEN7_L3BANK2X_CLOCK_GATE_DISABLE);
 
-	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
-
 	/*
 	 * BSpec says this must be set, even though
 	 * WaDisable4x2SubspanOptimization isn't listed for VLV.
@@ -6287,9 +6296,7 @@  static void cherryview_init_clock_gating(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
-
-	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
+	vlv_init_display_clock_gating(dev_priv);
 
 	/* WaVSRefCountFullforceMissDisable:chv */
 	/* WaDSRefCountFullforceMissDisable:chv */