[PATCH 00/14] drm/kms: Stop registering multiple /sys/class/backlight devs for a single display

[Hans de Goede <hdegoede@redhat.com>]

Hi All,

As mentioned in my RFC titled "drm/kms: control display brightness through
drm_connector properties":
https://lore.kernel.org/dri-devel/0d188965-d809-81b5-74ce-7d30c49fee2d@redhat.com/

The first step towards this is to deal with some existing technical debt
in backlight handling on x86/ACPI boards, specifically we need to stop
registering multiple /sys/class/backlight devs for a single display.

This series implements my RFC describing my plan for these cleanups:
https://lore.kernel.org/dri-devel/98519ba0-7f18-201a-ea34-652f50343158@redhat.com/

Specifically patches 1-6 implement the "Fixing kms driver unconditionally
register their "native" backlight dev" part.

And patches 7-14 implement the "Fixing acpi_video0 getting registered for
a brief time" time.

Note this series does not deal yet with the "Other issues" part, I plan
to do a follow up series for that.

The changes in this series are good to have regardless of the further
"drm/kms: control display brightness through drm_connector properties"
plans. So I plan to push these upstream once they are ready (once
reviewed). Since this crosses various subsystems / touches multiple
kms drivers my plan is to provide an immutable branch based on say
5.19-rc1 and then have that get merged into all the relevant trees.

Please review.

Regards,

Hans


Hans de Goede (14):
  ACPI: video: Add a native function parameter to
    acpi_video_get_backlight_type()
  drm/i915: Don't register backlight when another backlight should be
    used
  drm/amdgpu: Don't register backlight when another backlight should be
    used
  drm/radeon: Don't register backlight when another backlight should be
    used
  drm/nouveau: Don't register backlight when another backlight should be
    used
  ACPI: video: Drop backlight_device_get_by_type() call from
    acpi_video_get_backlight_type()
  ACPI: video: Remove acpi_video_bus from list before tearing it down
  ACPI: video: Simplify acpi_video_unregister_backlight()
  ACPI: video: Make backlight class device registration a separate step
  ACPI: video: Remove code to unregister acpi_video backlight when a
    native backlight registers
  drm/i915: Call acpi_video_register_backlight()
  drm/nouveau: Register ACPI video backlight when nv_backlight
    registration fails
  drm/amdgpu: Register ACPI video backlight when skipping amdgpu
    backlight registration
  drm/radeon: Register ACPI video backlight when skipping radeon
    backlight registration

 drivers/acpi/acpi_video.c                     | 69 ++++++++++++++-----
 drivers/acpi/video_detect.c                   | 53 +++-----------
 drivers/gpu/drm/Kconfig                       |  2 +
 .../gpu/drm/amd/amdgpu/atombios_encoders.c    | 14 +++-
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  9 +++
 .../gpu/drm/i915/display/intel_backlight.c    |  7 ++
 drivers/gpu/drm/i915/display/intel_display.c  |  1 +
 drivers/gpu/drm/i915/display/intel_opregion.c |  2 +-
 drivers/gpu/drm/nouveau/nouveau_backlight.c   | 14 ++++
 drivers/gpu/drm/radeon/atombios_encoders.c    |  7 ++
 drivers/gpu/drm/radeon/radeon_encoders.c      | 11 ++-
 .../gpu/drm/radeon/radeon_legacy_encoders.c   |  7 ++
 drivers/platform/x86/acer-wmi.c               |  2 +-
 drivers/platform/x86/asus-laptop.c            |  2 +-
 drivers/platform/x86/asus-wmi.c               |  4 +-
 drivers/platform/x86/compal-laptop.c          |  2 +-
 drivers/platform/x86/dell/dell-laptop.c       |  2 +-
 drivers/platform/x86/eeepc-laptop.c           |  2 +-
 drivers/platform/x86/fujitsu-laptop.c         |  4 +-
 drivers/platform/x86/ideapad-laptop.c         |  2 +-
 drivers/platform/x86/intel/oaktrail.c         |  2 +-
 drivers/platform/x86/msi-laptop.c             |  2 +-
 drivers/platform/x86/msi-wmi.c                |  2 +-
 drivers/platform/x86/samsung-laptop.c         |  2 +-
 drivers/platform/x86/sony-laptop.c            |  2 +-
 drivers/platform/x86/thinkpad_acpi.c          |  4 +-
 drivers/platform/x86/toshiba_acpi.c           |  2 +-
 include/acpi/video.h                          |  8 ++-
 28 files changed, 156 insertions(+), 84 deletions(-)

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2.36.0