ROSA Linux Bugzilla – Bug 5961
Brightness keys (Fn+F5, Fn+F6) doesn't work on ASUS N751J
Last modified: 2015-08-20 18:55:39 MSD
When I press buttons for changing brightness it doesn't work.
ACPI backlight working fine, I can easily change brighntess using power widget in KDE SC for example.
HW probe after pressing keys: http://hw.rosalinux.ru/index.php?probe=6aa72e5950
Created attachment 4215 [details]
Created attachment 4216 [details]
dmesg|grep 'ACPI: Video'
[ 1.818851] ACPI: Video Device [PEGP] (multi-head: yes rom: yes post: no)
[ 1.822038] ACPI: Video Device [GFX0] (multi-head: yes rom: no post: no)
when try to use acpidump:
jarnvidr ~ # acpidump -o acpidump.txt
Linux version not implemented yet
Could not get ACPI tables, AE_SUPPORT
acpidump.txt is empty.
Created attachment 4217 [details]
After updating acpica package I can make dump from ACPI table. All utilities runned on 4.1.6 kernel due bug #5962.
All programs was runned using this document: https://wiki.ubuntu.com/Kernel/Debugging/Backlight
Created attachment 4218 [details]
After adding grub option "acpi_backlight=vendor" backight is totally refuse to work. Returning back default backlight option.
After some experiments I found a workaround solution for this laptop. For activating backlight keys you need fix /etc/default/grub and add in the end of GRUB_CMDLINE_LINUX_DEFAULT line "acpi_osi=" option (without quotes).
Example: GRUB_CMDLINE_LINUX_DEFAULT='splash=silent logo.nologo acpi_osi='
Then run update-grub2 command under root user.