Re: [Intel-gfx] [RFC v2 05/22] drm/i915/xelpd: Define Degamma Lut range struct for HDR planes

Harry Wentland
2021-11-11T15:17:27Z

On 2021-09-06 17:38, Uma Shankar wrote:
> Define the structure with XE_LPD degamma lut ranges. HDR and SDR
> planes have different capabilities, implemented respective
> structure for the HDR planes.
>
> Signed-off-by: Uma Shankar <uma.shankar@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_color.c | 52 ++++++++++++++++++++++
> 1 file changed, 52 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index afcb4bf3826c..6403bd74324b 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -2092,6 +2092,58 @@ static void icl_read_luts(struct intel_crtc_state *crtc_state)
> }
> }
>
> + /* FIXME input bpc? */
> +__maybe_unused
> +static const struct drm_color_lut_range d13_degamma_hdr[] = {
> + /* segment 1 */
> + {
> + .flags = (DRM_MODE_LUT_GAMMA |
> + DRM_MODE_LUT_REFLECT_NEGATIVE |
> + DRM_MODE_LUT_INTERPOLATE |
> + DRM_MODE_LUT_NON_DECREASING),
> + .count = 128,
> + .input_bpc = 24, .output_bpc = 16,
> + .start = 0, .end = (1 << 24) - 1,
> + .min = 0, .max = (1 << 24) - 1,
> + },
> + /* segment 2 */
> + {
> + .flags = (DRM_MODE_LUT_GAMMA |
> + DRM_MODE_LUT_REFLECT_NEGATIVE |
> + DRM_MODE_LUT_INTERPOLATE |
> + DRM_MODE_LUT_REUSE_LAST |
> + DRM_MODE_LUT_NON_DECREASING),
> + .count = 1,
> + .input_bpc = 24, .output_bpc = 16,
> + .start = (1 << 24) - 1, .end = 1 << 24,
> + .min = 0, .max = (1 << 27) - 1,
> + },
> + /* Segment 3 */
> + {
> + .flags = (DRM_MODE_LUT_GAMMA |
> + DRM_MODE_LUT_REFLECT_NEGATIVE |
> + DRM_MODE_LUT_INTERPOLATE |
> + DRM_MODE_LUT_REUSE_LAST |
> + DRM_MODE_LUT_NON_DECREASING),
> + .count = 1,
> + .input_bpc = 24, .output_bpc = 16,
> + .start = 1 << 24, .end = 3 << 24,
> + .min = 0, .max = (1 << 27) - 1,
> + },
> + /* Segment 4 */
> + {
> + .flags = (DRM_MODE_LUT_GAMMA |
> + DRM_MODE_LUT_REFLECT_NEGATIVE |
> + DRM_MODE_LUT_INTERPOLATE |
> + DRM_MODE_LUT_REUSE_LAST |
> + DRM_MODE_LUT_NON_DECREASING),
> + .count = 1,
> + .input_bpc = 24, .output_bpc = 16,
> + .start = 3 << 24, .end = 7 << 24,
> + .min = 0, .max = (1 << 27) - 1,
> + },
> +};

If I understand this right, userspace would need this definition in order
to populate the degamma blob. Should this sit in a UAPI header?

Harry

> +
> void intel_color_init(struct intel_crtc *crtc)
> {
> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>