[PATCH v3 0/2] drm/i915/display: Enable HDR over DP MST

[Gil Dekel <gildekel@google.com>]

Currently, the Intel display driver does not support HDR over DP MST
connections. This series enables this functionality.

To achieve this:
1. We refactor colorimetry capability queries to query and cache the value
   on a per-connector basis (for both SST and MST downstream sinks)
   instead of checking the root port's DPCD register directly (which returns
   false for MST hubs).
2. We update the MST stream configuration to compute the required VSC and
   HDR metadata SDPs.
3. We set the transcoder's Video DIP registers on stream enable and during
   fastsets (update_pipe) to propagate HDR metadata changes without forcing
   a full modeset.
4. We expose the max_bpc, HDR metadata, and DP Colorspace properties on
   MST connectors.

Link to v1/v2 discussion:
https://lore.kernel.org/r/20260625160020.2873859-1-gildekel@google.com

Changes in v3:
- Stripped Gerrit Change-Id tags from commit messages.
- Added Assisted-by: jetski:gemini-2.5-pro tags.

Changes in v2:
- Fixed critical Werror CI build break (-Wunused-but-set-variable) by
  removing unused display variable in intel_dp_compute_vsc_sdp().
- Resolved checkpatch warnings by hoisting variable declarations and
  restoring missing blank lines.
- Gated attaching MST HDR_OUTPUT_METADATA property on
  intel_dp_has_gamut_metadata_dip() for consistency with SST.
- Removed redundant direct max_bpc assignment on connector struct.

Gil Dekel (2):
  drm/i915/display: Cache DP colorimetry support per-connector
  drm/i915/display/mst: Enable HDR over DP MST

 .../drm/i915/display/intel_display_types.h    |  1 +
 drivers/gpu/drm/i915/display/intel_dp.c       | 25 ++++++++---
 drivers/gpu/drm/i915/display/intel_dp.h       |  8 ++++
 drivers/gpu/drm/i915/display/intel_dp_mst.c   | 44 +++++++++++++++++--
 4 files changed, 68 insertions(+), 10 deletions(-)

--
Gil Dekel, Software Engineer, Google / ChromeOS Display and Graphics