I have been struggling now for an inordinate amount of time trying to get the brightness adjustment working in Ubuntu.
I am running Ubuntu 12.04 on a Lenovo V570 Laptop.
I have tried all of the adjustments I can find to "fix brightness control" in the /etc/default/grub
file with the following results (before you ask, yes I did run sudo update-grub
and sudo reboot
after each change):
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi="
Result: No response to buttons, slider has no affect.
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"
Result: No response to buttons, slider has no affect.
GRUB_CMDLINE_LINUX_DEFAULT="splash quiet acpi_osi='!Windows 2012'"
Result: Limited response to buttons from OS (slider only moves down one tick, then sticks), no dimming, slider has no affect.
GRUB_CMDLINE_LINUX_DEFAULT="splash quiet"
Result: OS responds to buttons, but screen does not dim. Slider has no affect.
Am I missing something? What can I do to adjust the brightness?
Update:
I did more searching, and I found that in /sys/class/backlight
I have both acpi_video0
and intel_backlight
. By changing the "brightness" file in each of these folders, I discovered, that editing the /sys/class/backlight/intel_backlight/brightness
changed the actual brightness setting on my screen.
How do I get Ubuntu to adjust this setting? Any hope of getting my function keys to also adjust it?
Update2:
As requested, here is the output from lspci
:
$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)