[Intel-gfx] [PATCH 03/13] drm/i915: Precompute gamma_mode

[Matt Roper]

On Fri, Jan 11, 2019 at 07:08:13PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> We shouldn't be computing gamma mode during the commit phase.
> Move it to the check phase.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Looks like this also drops the posting reads, but I don't see anything
in the bspec that indicates those were necessary in the first place.

> ---
>  drivers/gpu/drm/i915/intel_color.c | 44 +++++++++++++++++-------------
>  1 file changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
> index 37fd9ddf762e..b10e66ce3970 100644
> --- a/drivers/gpu/drm/i915/intel_color.c
> +++ b/drivers/gpu/drm/i915/intel_color.c
> @@ -375,8 +375,7 @@ static void haswell_load_luts(struct intel_crtc_state *crtc_state)
>  		reenable_ips = true;
>  	}
>  
> -	crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
> -	I915_WRITE(GAMMA_MODE(crtc->pipe), GAMMA_MODE_MODE_8BIT);
> +	I915_WRITE(GAMMA_MODE(crtc->pipe), crtc_state->gamma_mode);
>  
>  	i9xx_load_luts(crtc_state);
>  
> @@ -476,9 +475,7 @@ static void broadwell_load_luts(struct intel_crtc_state *crtc_state)
>  	bdw_load_gamma_lut(crtc_state,
>  			   INTEL_INFO(dev_priv)->color.degamma_lut_size);
>  
> -	crtc_state->gamma_mode = GAMMA_MODE_MODE_SPLIT;
> -	I915_WRITE(GAMMA_MODE(pipe), GAMMA_MODE_MODE_SPLIT);
> -	POSTING_READ(GAMMA_MODE(pipe));
> +	I915_WRITE(GAMMA_MODE(pipe), crtc_state->gamma_mode);
>  
>  	/*
>  	 * Reset the index, otherwise it prevents the legacy palette to be
> @@ -532,9 +529,7 @@ static void glk_load_luts(struct intel_crtc_state *crtc_state)
>  
>  	bdw_load_gamma_lut(crtc_state, 0);
>  
> -	crtc_state->gamma_mode = GAMMA_MODE_MODE_10BIT;
> -	I915_WRITE(GAMMA_MODE(pipe), GAMMA_MODE_MODE_10BIT);
> -	POSTING_READ(GAMMA_MODE(pipe));
> +	I915_WRITE(GAMMA_MODE(pipe), crtc_state->gamma_mode);
>  }
>  
>  /* Loads the palette/gamma unit for the CRTC on CherryView. */
> @@ -608,29 +603,40 @@ void intel_color_load_luts(struct intel_crtc_state *crtc_state)
>  int intel_color_check(struct intel_crtc_state *crtc_state)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
> +	const struct drm_property_blob *gamma_lut = crtc_state->base.gamma_lut;
> +	const struct drm_property_blob *degamma_lut = crtc_state->base.degamma_lut;
>  	size_t gamma_length, degamma_length;
>  
>  	degamma_length = INTEL_INFO(dev_priv)->color.degamma_lut_size;
>  	gamma_length = INTEL_INFO(dev_priv)->color.gamma_lut_size;
>  
>  	/*
> -	 * We allow both degamma & gamma luts at the right size or
> -	 * NULL.
> +	 * We also allow no degamma lut/ctm and a gamma lut at the legacy
> +	 * size (256 entries).
>  	 */

Minor nit:  now that the order of tests is swapped, you probably want
to move the "also" from this comment down to the one below.

Otherwise,

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> -	if ((!crtc_state->base.degamma_lut ||
> -	     drm_color_lut_size(crtc_state->base.degamma_lut) == degamma_length) &&
> -	    (!crtc_state->base.gamma_lut ||
> -	     drm_color_lut_size(crtc_state->base.gamma_lut) == gamma_length))
> +	if (crtc_state_is_legacy_gamma(crtc_state)) {
> +		crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
>  		return 0;
> +	}
>  
>  	/*
> -	 * We also allow no degamma lut/ctm and a gamma lut at the legacy
> -	 * size (256 entries).
> +	 * We allow both degamma & gamma luts at the right size or
> +	 * NULL.
>  	 */
> -	if (crtc_state_is_legacy_gamma(crtc_state))
> -		return 0;
> +	if (degamma_lut && drm_color_lut_size(degamma_lut) != degamma_length)
> +		return -EINVAL;
> +
> +	if (gamma_lut && drm_color_lut_size(gamma_lut) != gamma_length)
> +		return -EINVAL;
> +
> +	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
> +		crtc_state->gamma_mode = GAMMA_MODE_MODE_10BIT;
> +	else if (INTEL_GEN(dev_priv) >= 9 || IS_BROADWELL(dev_priv))
> +		crtc_state->gamma_mode = GAMMA_MODE_MODE_SPLIT;
> +	else
> +		crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
>  
> -	return -EINVAL;
> +	return 0;
>  }
>  
>  void intel_color_init(struct intel_crtc *crtc)
> -- 
> 2.19.2
> 

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795