[Intel-gfx] [PATCH 09/11] drm/i915: Reject YCbCr output with degamma+gamma on pre-icl

[Nautiyal, Ankit K]

LGTM.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>

On 10/26/2022 5:09 PM, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Since the pipe CSC sits between the degamma and gamma LUTs there
> is no way to make us it for RGB->YCbCr conversion when both LUTs
> are also active. Simply reject such combos.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_color.c | 18 ++++++++++++++++--
>   1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index 435394cad359..926784f266f2 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -1556,7 +1556,14 @@ static int ivb_color_check(struct intel_crtc_state *crtc_state)
>   	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
>   	    crtc_state->hw.ctm) {
>   		drm_dbg_kms(&i915->drm,
> -			    "YCBCR and CTM together are not possible\n");
> +			    "YCbCr and CTM together are not possible\n");
> +		return -EINVAL;
> +	}
> +
> +	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
> +	    crtc_state->hw.degamma_lut && crtc_state->hw.gamma_lut) {
> +		drm_dbg_kms(&i915->drm,
> +			    "YCbCr and degamma+gamma together are not possible\n");
>   		return -EINVAL;
>   	}
>   
> @@ -1622,7 +1629,14 @@ static int glk_color_check(struct intel_crtc_state *crtc_state)
>   	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
>   	    crtc_state->hw.ctm) {
>   		drm_dbg_kms(&i915->drm,
> -			    "YCBCR and CTM together are not possible\n");
> +			    "YCbCr and CTM together are not possible\n");
> +		return -EINVAL;
> +	}
> +
> +	if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB &&
> +	    crtc_state->hw.degamma_lut && crtc_state->hw.gamma_lut) {
> +		drm_dbg_kms(&i915->drm,
> +			    "YCbCr and degamma+gamma together are not possible\n");
>   		return -EINVAL;
>   	}
>