I bought the new ultrabook Sony VAIO SVT1311. Many things work but brightness control doesn't. I see the splash bubble (that reacts to Fn+F5 and Fn+F6) but the brightness doesn't change. It stays permanent at 100% and I can't do anything with it. The graphics card is integrated Intel HD3000.
2 Answers
To get working brightness key. try following
execute sudo gedit /etc/default/grub
Change this line
GRUB_CMLINE_LINUX_DEFAULT="quiet splash"
to something like below
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"
Execute sudo update-grub
and reboot . See if brightness keys are working.
It is still possible ubuntu won't remember your brightness settings. So you have to change brightness each time.
Please let us know the result as many sony users are facing this problem.
Update: This is for setting brightness manually.
Try following for both path shown by ls /sys/class/backlight/*/brightness
and replace accordingly. Most probably the intel one should work.
Get the maximum brightness:
cat /sys/class/backlight/intel_backlight/max_brightness
Try a lower value to set the brightness, say output is 2048 so I will try with half of it
echo 1024| sudo tee /sys/class/backlight/intel_backlight/brightness
If this works, make this happen in each login automatically by doing the following
sudo gedit /etc/rc.local
Enter this line just before exit 0
. It should look like
echo YOUR_VALUE_HERE > /sys/class/backlight/intel_backlight/brightness
exit 0
I have another question. Does your system has hybrid graphics card? whats the output of lspci | grep vga
?
Also you can try with xdotool
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I changed grub settings: now the bubble can switch between 90% and 100%, but anyway the brightness remains maximum. This notebook hasn't light sensor so the way under the link is not for me. Jun 22, 2012 at 11:35
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Yes, it works! Only with intel (max - 4882). With /sys/class/backlight/sony/brightness (max - 7) it doesn't. If I set value to rc.local, this will be for all session and coldn't be changed during work. Jun 22, 2012 at 12:38
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yea.. update
rc.local
. And accept this answer by clicking the tick button on upper left of my answer– Web-EJun 22, 2012 at 12:46
adding acpi_backlight=vendor to the grub command line like suggested above did not help in my case. My workaround was to use the intel_backlight command from command line.
example:
# set the brightness down to 20%:
intel_backlight 20
ls /sys/class/backlight/*/brightness