The value in /sys/devices/virtual/backlight/acpi_video0/brightness also changes whenever one of the three events mentioned above happens.
Today I found the following: When I set xrandr --output LVDS --set BACKLIGHT_CONTROL native then I can control the brightness using the function keys, xbacklight and xrandr. The gnome applet also works, but is too slow to be useful. In this mode the values in /sys and /proc/acpi don't change anymore. Dis/Connecting the A/C power has no impact in this mode. However, there is still a dependency on the power status during boot. It seems that the maximum brightness available is still set at that time. I have not found a way to increase the brightness beyond that level except plug-in & reboot. xrandr --output LVDS --set BACKLIGHT_CONTROL kernel switches everything back to as it was before. -- mute, brightness buttons on new HP 6930p laptop https://bugs.launchpad.net/bugs/284319 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
