[Intel-gfx] [PATCH 12/13] drm/i915: Turn off pipe CSC when it's not needed

[Matt Roper]

On Fri, Jan 11, 2019 at 07:08:22PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> As with pipe gamma we can avoid the potential precision loss from
> the pipe csc unit when there is no need to use it. And again
> we need the same logic for updating the planes.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

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

> ---
>  drivers/gpu/drm/i915/intel_color.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
> index a8b7428a64bf..789b04bb51d2 100644
> --- a/drivers/gpu/drm/i915/intel_color.c
> +++ b/drivers/gpu/drm/i915/intel_color.c
> @@ -659,7 +659,8 @@ intel_color_add_affected_planes(struct intel_crtc_state *new_crtc_state)
>  		intel_atomic_get_old_crtc_state(state, crtc);
>  	struct intel_plane *plane;
>  
> -	if (new_crtc_state->gamma_enable == old_crtc_state->gamma_enable)
> +	if (new_crtc_state->gamma_enable == old_crtc_state->gamma_enable &&
> +	    new_crtc_state->csc_enable == old_crtc_state->csc_enable)
>  		return 0;
>  
>  	for_each_intel_plane_on_crtc(&dev_priv->drm, crtc, plane) {
> @@ -684,6 +685,7 @@ int intel_color_check(struct intel_crtc_state *crtc_state)
>  	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;
> +	bool limited_color_range = false;
>  	int ret;
>  
>  	degamma_length = INTEL_INFO(dev_priv)->color.degamma_lut_size;
> @@ -693,7 +695,11 @@ int intel_color_check(struct intel_crtc_state *crtc_state)
>  
>  	if (INTEL_GEN(dev_priv) >= 9 ||
>  	    IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
> -		crtc_state->csc_enable = true;
> +		limited_color_range = crtc_state->limited_color_range;
> +
> +	crtc_state->csc_enable =
> +		crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB ||
> +		crtc_state->base.ctm || limited_color_range;
>  
>  	ret = intel_color_add_affected_planes(crtc_state);
>  	if (ret)
> -- 
> 2.19.2
> 

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