|Summary:||Backlight keys do not work on Lenovo Yoga|
|Product:||ACPI||Reporter:||Kevin Smith (thirdwiggin)|
|Attachments:||Lenovo Yoga 13 ACPI dump|
Description Kevin Smith 2013-10-26 21:13:03 UTC
Created attachment 112341 [details] Lenovo Yoga 13 ACPI dump I have a problem very similar to bug 51231, but on a Lenovo Yoga 13. The brightness keys in X do not change the backlight. Booting with normal kernel options results in two entries in /sys/class/backlight: acpi_video0 and intel_backlight. acpi_video0 has no effect on the brightness, but intel_backlight does. When the brightness keys are pressed, X is changing the acpi_video0 brightness. Booting with acpi_osi="!Windows 2012" does not seem to make a difference. Booting with acpi_backlight=vendor creates: ideapad -> ../../devices/platform/ideapad/backlight/ideapad intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight instead of acpi_video0. This one does not work either. (intel_backlight still works). ACPI dump output is attached. I am glad to try patches, boot options, etc.
Comment 1 Kevin Smith 2013-10-27 18:11:10 UTC
I tried v5 of the patch series attached to bug 51231 on 3.12.0-rc5 on my Yoga, and can verify that booting with video.use_native_backlight=1 corrects the problem. (At first glance, I thought the patch series only fixed the problem for models using the thinkpad driver, so didn't look into it.) acpi_video0 does not appear, and so X uses intel_backlight instead. This is good enough for me to consider the issue resolved, but I'm still glad to test out any changes.