Re: [PATCH 6/6] drm/i915: HSW FBC WaFbcDisableDpfcClockGating

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

On Thu, Apr 25, 2013 at 02:15:25PM -0300, Rodrigo Vivi wrote:
> Display register 46500h bit 23 must be set to 1b for the entire time that
> Frame Buffer Compression is enabled.
> 
> v2: Ville suggested to enable it back when disabling fbc to avoid wasting
>     power.
> 
> v3: RMW to preserve other bits (by Ville)
> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h |  3 +++
>  drivers/gpu/drm/i915/intel_pm.c | 10 ++++++++++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 922a7a0..82eaa69 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -871,6 +871,9 @@
>  					     _HSW_PIPE_SLICE_CHICKEN_1_A, + \
>  					     _HSW_PIPE_SLICE_CHICKEN_1_B)
>  
> +#define HSW_CLKGATE_DISABLE_PART_1	0x46500
> +#define   HSW_DPFC_GATING_DISABLE	(1<<23)
> +
>  /*
>   * GPIO regs
>   */
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 9d36158..67b6eab 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -248,6 +248,12 @@ static void ironlake_disable_fbc(struct drm_device *dev)
>  				   I915_READ(ILK_DSPCLK_GATE_D) &
>  				   ~ILK_DPFCUNIT_CLOCK_GATE_DISABLE);
>  
> +		if(IS_HASWELL(dev))
> +			/* WaFbcDisableDpfcClockGating */
> +			I915_WRITE(HSW_CLKGATE_DISABLE_PART_1,
> +				   I915_READ(HSW_CLKGATE_DISABLE_PART_1) &
> +				   ~HSW_DPFC_GATING_DISABLE);
> +
>  		DRM_DEBUG_KMS("disabled FBC\n");
>  	}
>  }
> @@ -285,6 +291,10 @@ static void gen7_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
>  		/* WaFbcAsynchFlipDisableFbcQueue */
>  		I915_WRITE(HSW_PIPE_SLICE_CHICKEN_1(intel_crtc->pipe),
>  			   HSW_BYPASS_FBC_QUEUE);
> +		/* WaFbcDisableDpfcClockGating */
> +		I915_WRITE(HSW_CLKGATE_DISABLE_PART_1,
> +			   I915_READ(HSW_CLKGATE_DISABLE_PART_1) &
                                                                 ^

'|' again.

> +			   HSW_DPFC_GATING_DISABLE);
>  	}
>  
>  	I915_WRITE(SNB_DPFC_CTL_SA,
> -- 
> 1.8.1.4

-- 
Ville Syrjälä
Intel OTC