On Tue, 01 Jul 2025, Uma Shankar <uma.shan...@intel.com> wrote:
> RGB limited range should be selected only if explicitly asked by
> userspace by the broadcast RGB property with LIMITED_RANGE. This
> is mostly enabled in case of CEA modes.
>
> Display port by default uses Full Range, fixed the same. This will help
> set correct MSA information for colorimetry. Fixes a CTS issue wrt
> colorimetry.
If we decide to go this way, the commit message *must* capture the
history precisely, and not pretend this is the only way and everything
that was before was wrong. And that we're primarily doing it to pass
CTS.
> Signed-off-by: Uma Shankar <uma.shan...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 21 +++++++--------------
> 1 file changed, 7 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index f48912f308df..8758b9d60d5e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2708,8 +2708,6 @@ bool intel_dp_limited_color_range(const struct
> intel_crtc_state *crtc_state,
> {
> const struct intel_digital_connector_state *intel_conn_state =
> to_intel_digital_connector_state(conn_state);
> - const struct drm_display_mode *adjusted_mode =
> - &crtc_state->hw.adjusted_mode;
>
> /*
> * Our YCbCr output is always limited range.
> @@ -2721,18 +2719,13 @@ bool intel_dp_limited_color_range(const struct
> intel_crtc_state *crtc_state,
> if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB)
> return false;
>
> - if (intel_conn_state->broadcast_rgb == INTEL_BROADCAST_RGB_AUTO) {
> - /*
> - * See:
> - * CEA-861-E - 5.1 Default Encoding Parameters
> - * VESA DisplayPort Ver.1.2a - 5.1.1.1 Video Colorimetry
> - */
> - return crtc_state->pipe_bpp != 18 &&
> - drm_default_rgb_quant_range(adjusted_mode) ==
> - HDMI_QUANTIZATION_RANGE_LIMITED;
> - } else {
> - return intel_conn_state->broadcast_rgb ==
> - INTEL_BROADCAST_RGB_LIMITED;
> + switch (intel_conn_state->broadcast_rgb) {
> + case INTEL_BROADCAST_RGB_LIMITED:
> + return true;
> + case INTEL_BROADCAST_RGB_FULL:
> + case INTEL_BROADCAST_RGB_AUTO:
> + default:
> + return false;
> }
That's just:
return intel_conn_state->broadcast_rgb == INTEL_BROADCAST_RGB_LIMITED;
> }
--
Jani Nikula, Intel
