So, as a number of users seem to be experiencing, I am unable to change brightness on my laptop. Using the Brightness and Lock in settings, the slider moves but brightness does not adjust. The fn keys work for volume but not for brightness. I have updated my drivers and installed all updates, however the brightness is still at maximum.
I have heard that opening sudo gedit /etc/x11/xorg.conf
and entering Option "RegistryDwords" "EnableBrightnessControl=1"
can fix this, however when opening xorg.conf through Terminal I am greeted with a blank document... Not very reassuring.
Toshiba L750 Laptop
Nvidia Graphics Card
Dual boot with Windows
/etc/X11/xorg.conf
.. capitalX
. Also please post result ofls /sys/class/backlight/*/brightness
. Is your system optimus enabled. what is output oflspci | grep VGA
?ls /sys/class/backlight/*/brightness
I get:/sys/class/backlight/acpi_video0/brightness
/sys/class/backlight/toshiba/brightness
Unsure how to tell if Optimus enabled, as forlspci | grep VGA
I get:01:00.0 VGA compatible controller: NVIDIA Corporation Device 0dec (rev a1)
echo 1024| sudo tee /sys/class/backlight/toshiba/brightness
andecho 1024| sudo tee /sys/class/backlight/acpi_video0/brightness
I am met with Invalid Argument