[Intel-gfx] [PATCH 2/3] drm/i915/xelpd: Enable Pipe Degamma

[Ville Syrjälä]

On Wed, Nov 24, 2021 at 01:06:48AM +0530, Uma Shankar wrote:
> Enable Pipe Degamma for XE_LPD. Extend the legacy implementation
> to incorparate the extended lut size for XE_LPD.
> 
> Signed-off-by: Uma Shankar <uma.shankar at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_color.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index e529dbeee525..81046d5ab509 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -815,6 +815,12 @@ static void glk_load_degamma_lut(const struct intel_crtc_state *crtc_state)
>  	enum pipe pipe = crtc->pipe;
>  	int i, lut_size = INTEL_INFO(dev_priv)->color.degamma_lut_size;
>  	const struct drm_color_lut *lut = crtc_state->hw.degamma_lut->data;
> +	u32 extended_lut_size;
> +
> +	if (DISPLAY_VER(dev_priv) >= 13)
> +		extended_lut_size = 131;
> +	else
> +		extended_lut_size = 35;

Can you extract that into a small helper? IIRC I did that for the
internal version already.

>  
>  	/*
>  	 * When setting the auto-increment bit, the hardware seems to
> @@ -827,8 +833,8 @@ static void glk_load_degamma_lut(const struct intel_crtc_state *crtc_state)
>  
>  	for (i = 0; i < lut_size; i++) {
>  		/*
> -		 * First 33 entries represent range from 0 to 1.0
> -		 * 34th and 35th entry will represent extended range
> +		 * First lut_size entries represent range from 0 to 1.0
> +		 * 3 additional lut entries will represent extended range
>  		 * inputs 3.0 and 7.0 respectively, currently clamped
>  		 * at 1.0. Since the precision is 16bit, the user
>  		 * value can be directly filled to register.
> @@ -844,7 +850,7 @@ static void glk_load_degamma_lut(const struct intel_crtc_state *crtc_state)
>  	}
>  
>  	/* Clamp values > 1.0. */
> -	while (i++ < 35)
> +	while (i++ < extended_lut_size)
>  		intel_de_write_fw(dev_priv, PRE_CSC_GAMC_DATA(pipe), 1 << 16);
>  
>  	intel_de_write_fw(dev_priv, PRE_CSC_GAMC_INDEX(pipe), 0);
> -- 
> 2.25.1

-- 
Ville Syrjälä
Intel