@Tito and other folks with /sys/class/backlight/acpi_video0: To disable the "acpi_video0" backlight, boot with this kernel parameter[1]:
acpi_backlight=vendor However note that when I do so on my Lenovo Thinkpad, acpi_video0 disappears but then /sys/class/backlight/thinkpad_backlight appears in its place, so... To disable "thinkpad_backlight", boot with this kernel parameter also: thinkpad_acpi.brightness_enable=0 Tito, please try booting with both of those parameters (together) and report your results. [1] To add kernel boot parameters, append them to the "linux" or "kernel" boot line as demonstrated here: https://help.ubuntu.com/community/Grub2#Editing%20Menus%20During%20Boot https://help.ubuntu.com/community/BootOptions#Change%20Boot%20Options%20Temporarily%20For%20An%20Existing%20Installation -- Screen brightness control fails on Dell Studio 1558 https://bugs.launchpad.net/bugs/568611 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs