Hi Akihiko, On 10/24/22 13:34, Akihiko Odaki 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. I appreciate your work on this, but what this in essence does is it allows 2 backlight drivers (vendor + native) to get registered for the same panel again. While the whole goal of the backlight refactor series landing in 6.1 was to make it so that there always is only *1* backlight device registered instead of (possibly) registering multiple and letting userspace figure it out. It is also important to only always have 1 backlight device per panel for further upcoming changes. So nack for this solution, sorry. I am aware that this breaks backlight control on some Chromebooks, this was already reported and I wrote a long reply explaining why things are done the way they are done now and also suggesting 2 possible (much simpler) fixes, see: https://lore.kernel.org/linux-acpi/42a5f2c9-a1dc-8fc0-7334-fe6c390ecfbb@xxxxxxxxxx/ Unfortunately the reported has not followed-up on this and I don't have the hardware to test this myself. Can you please try implementing 1 of the fixes suggested there and then submit that upstream ? Regards, Hans > > Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx> > > 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(-) >