On Mon, 24 Oct 2022, Akihiko Odaki [off-list ref] wrote:

Commit 2600bfa3df99 ("ACPI: video: Add acpi_video_backlight_use_native()
helper") and following commits made native backlight unavailable if
CONFIG_ACPI_VIDEO is set and the backlight feature of ACPI video is
unavailable, which broke the backlight functionality on Lenovo ThinkPad
C13 Yoga Chromebook. Allow to fall back to native backlight in such
cases.

Where's the bug report with relevant logs, kconfigs, etc?

BR,
Jani.

Signed-off-by: Akihiko Odaki <redacted>

Akihiko Odaki (22):
  drm/i915/opregion: Improve backlight request condition
  ACPI: video: Introduce acpi_video_get_backlight_types()
  LoongArch: Use acpi_video_get_backlight_types()
  platform/x86: acer-wmi: Use acpi_video_get_backlight_types()
  platform/x86: asus-laptop: Use acpi_video_get_backlight_types()
  platform/x86: asus-wmi: Use acpi_video_get_backlight_types()
  platform/x86: compal-laptop: Use acpi_video_get_backlight_types()
  platform/x86: eeepc-laptop: Use acpi_video_get_backlight_types()
  platform/x86: fujitsu-laptop: Use acpi_video_get_backlight_types()
  platform/x86: ideapad-laptop: Use acpi_video_get_backlight_types()
  platform/x86: msi-laptop: Use acpi_video_get_backlight_types()
  platform/x86: msi-wmi: Use acpi_video_get_backlight_types()
  platform/x86: nvidia-wmi-ec-backlight: Use
    acpi_video_get_backlight_types()
  platform/x86: panasonic-laptop: Use acpi_video_get_backlight_types()
  platform/x86: samsung-laptop: Use acpi_video_get_backlight_types()
  platform/x86: sony-laptop: Use acpi_video_get_backlight_types()
  platform/x86: thinkpad_acpi: Use acpi_video_get_backlight_types()
  platform/x86: toshiba_acpi: Use acpi_video_get_backlight_types()
  platform/x86: dell-laptop: Use acpi_video_get_backlight_types()
  platform/x86: intel_oaktrail: Use acpi_video_get_backlight_types()
  ACPI: video: Remove acpi_video_get_backlight_type()
  ACPI: video: Fallback to native backlight

 Documentation/gpu/todo.rst                    |  8 +--
 drivers/acpi/acpi_video.c                     |  2 +-
 drivers/acpi/video_detect.c                   | 54 ++++++++++---------
 drivers/gpu/drm/i915/display/intel_opregion.c |  3 +-
 drivers/platform/loongarch/loongson-laptop.c  |  4 +-
 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 +-
 .../platform/x86/nvidia-wmi-ec-backlight.c    |  2 +-
 drivers/platform/x86/panasonic-laptop.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 +-
 drivers/video/backlight/backlight.c           | 18 +++++++
 include/acpi/video.h                          | 21 ++++----
 include/linux/backlight.h                     |  1 +
 25 files changed, 85 insertions(+), 66 deletions(-)

-- 
Jani Nikula, Intel Open Source Graphics Center