[Intel-gfx] [PATCH 7/7] drm/i915/psr: Implement PSR2 w/a for skl/kbl

[Ville Syrjälä]

On Wed, May 18, 2016 at 06:47:16PM +0200, Daniel Vetter wrote:
> Found this while browsing Bspec. Looks like it applies to both skl and
> kbl.

BXT too perhaps. Actually PSR2_CTL says SKL+, but CHICKEN_MISC_1 seems
to say SKL only.

w/a db is having issues it seems, so I can't check if there's anything
relevant there.

> 
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Sonika Jindal <sonika.jindal at intel.com>
> Cc: Durgadoss R <durgadoss.r at intel.com>
> Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan at intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h |  1 +
>  drivers/gpu/drm/i915/intel_pm.c | 13 +++++++++++--
>  2 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 0f99e67f2114..c51368744e9e 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6043,6 +6043,7 @@ enum skl_disp_power_wells {
>  #define CHICKEN_PAR1_1		_MMIO(0x42080)
>  #define  DPA_MASK_VBLANK_SRD	(1 << 15)
>  #define  FORCE_ARB_IDLE_PLANES	(1 << 14)
> +#define  SKL_EDP_PSR_FIX_RDWRAP	(1 << 3)
>  
>  #define _CHICKEN_PIPESL_1_A	0x420b0
>  #define _CHICKEN_PIPESL_1_B	0x420b4
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index e0d5405a8b15..c583d1de4555 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -6845,6 +6845,15 @@ static void gen8_set_l3sqc_credits(struct drm_i915_private *dev_priv,
>  	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
>  }
>  
> +static void skylake_init_clock_gating(struct drm_device *dev)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	/* See Bspec note for PSR2_CTL bit 31 */
> +	I915_WRITE(CHICKEN_PAR1_1,
> +		   I915_READ(CHICKEN_PAR1_1) | SKL_EDP_PSR_FIX_RDWRAP);
> +}
> +
>  static void broadwell_init_clock_gating(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -7307,9 +7316,9 @@ static void nop_init_clock_gating(struct drm_device *dev)
>  void intel_init_clock_gating_hooks(struct drm_i915_private *dev_priv)
>  {
>  	if (IS_SKYLAKE(dev_priv))
> -		dev_priv->display.init_clock_gating = nop_init_clock_gating;
> +		dev_priv->display.init_clock_gating = skylake_init_clock_gating;
>  	else if (IS_KABYLAKE(dev_priv))
> -		dev_priv->display.init_clock_gating = nop_init_clock_gating;
> +		dev_priv->display.init_clock_gating = skylake_init_clock_gating;
>  	else if (IS_BROXTON(dev_priv))
>  		dev_priv->display.init_clock_gating = bxt_init_clock_gating;
>  	else if (IS_BROADWELL(dev_priv))
> -- 
> 2.8.1
> 
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-- 
Ville Syrjälä
Intel OTC