[v2,0/4] Add support for fetching EDID from ACPI _DDC

Message

Mario Limonciello Jan. 30, 2024, 7:26 p.m. UTC

Some laptops ship an EDID in the BIOS encoded in the _DDC method that
differs than the EDID directly on the laptop panel for $REASONS.

This is the EDID that is used by the AMD Windows driver, and so sometimes
different results are found in different operating systems.

This series adds a new DRM helper that will use acpi_video to fetch the
EDID.

On amdgpu when an eDP panel is found the BIOS
is checked first for an EDID and that used as a preference if found.

On nouveau it replaces the previous local function doing a similar role.

This does *not* use struct drm_edid as this will require more involved
amdgpu display driver work that will come separately as part of follow-ups
to: https://lore.kernel.org/amd-gfx/[e-mail]/

Mario Limonciello (4):
  ACPI: video: Handle fetching EDID that is longer than 256 bytes
  drm: Add drm_get_acpi_edid() helper
  drm/amd: Fetch the EDID from _DDC if available for eDP
  drm/nouveau: Use drm_get_acpi_edid() helper

 drivers/acpi/acpi_video.c                     | 25 +++----
 drivers/gpu/drm/Kconfig                       |  4 +
 drivers/gpu/drm/amd/amdgpu/amdgpu.h           |  1 +
 .../gpu/drm/amd/amdgpu/amdgpu_connectors.c    |  4 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c       |  8 ++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++-
 .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c |  9 ++-
 drivers/gpu/drm/drm_edid.c                    | 73 +++++++++++++++++++
 drivers/gpu/drm/nouveau/nouveau_acpi.c        | 27 -------
 drivers/gpu/drm/nouveau/nouveau_acpi.h        |  2 -
 drivers/gpu/drm/nouveau/nouveau_connector.c   |  2 +-
 include/drm/drm_edid.h                        |  1 +
 12 files changed, 115 insertions(+), 51 deletions(-)