for ubuntu 16.04 on HP pavilion dv6 and Nvidia Graphic driver, the problem is the same.
xbacklight -set 100 ----> NOT WORKS xrandr --output LVDS-0 --set Backlight 100 ----> NOT WORKS xrandr --output LVDS-0 --brightness 1 ----> WORKS(IT HAS A DIFFERENT EFFECT!) echo 1 |sudo tee /sys/class/backlight/acpi_video0/brightness ----> WORKS -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1054298 Title: xbacklight doesn't work, but xrandr does and so does /sys/class/backlight Status in linux package in Ubuntu: Expired Bug description: Sony Vaio P Ubuntu Precise and Quantal kernel 3.5.0 gma500_gfx kernel driver modesetting xorg driver Assume the current quantal & quantal-proposed versions of everything. xbacklight doesn't work. No backlight change, and no output from the program. "xbacklight" and "xbacklight -get" show nothing, no output from the program at all. "xbacklight -set50" and "xbacklight-d :0 -set 50" does nothing nor prints any output. However both sysfs and xrandr work fine. Specifically: xrandr --verbose lists outputs and shows the main screen has backlight property, and "xrandr --output LVDS-0 --set backlight 50" changes the backlight brightness. And "cat /sys/class/backlight/psb-bl/actual_brightness" shows the current brightness, and "echo 50 >/sys/class/backlight/psb-bl/brightness" changes the brightness. I have written the following script to use in place of xbacklight: http://forums.bodhilinux.com/index.php?/topic/5985-brightness-scripts/page__view__findpost__p__56911 This script, both the sysfs and xrandr methods of it, works fine for me on the same machine. (for sysfs, I had to make a udev rule to allow users to write to the sysfs files, as noted on that page and in the --help output of the script) It requires zenity for the user interactive options. Not needed for the non-interactive options. -- bkw To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1054298/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
