ubuntu-x-swat team mailing list archive

[Tom Gelinas <562005@xxxxxxxxxxxxxxxxxx>]

The nvidiabl driver now detects ThinkPad T510s with model 4313CTO. This
will not allow gnome-power-manager to control the backlight, but at
least the keys will work....sort of. With autodetected values,
brightness can be turned down all the way, but can only be set to a
proper maximum by switching to a VT and turning the brightness down a
notch. If anyone would like to play around with backlight values, the
instructions below will get them set up. nvidiabl's source can be
modified to work with other ThinkPad models as well.

ACPI backlight control must be set to vendor, the thinkpad_acpi module's
brightness controls must be disabled and the brightness keys must be
bound using acpi events.

ACPI backlight controls can be set to vendor by setting
'GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor"' in
/etc/default/grub and then running update-grub.

thinkpad_acpi's brightness controls can be disabled by creating
/etc/modprobe.d/thinkpad_acpi.conf and adding the line "options
thinkpad_acpi brightness_enable=0".

nvidiabl source can be obtained from
https://github.com/guillaumezin/nvidiabl , then installed by dkms. The
scripts "nvidia_backlight_down.sh" and "nvidia_backlight_up.sh" should
be copied from the scripts folder to /etc/acpi.

Then the brightness keys can be bound to those scripts by
creating/filling the following files:

/etc/acpi/events/lenovo-4313cto-brightness-down
event=video LCD0 00000087 00000000
action=/etc/acpi/nvidia_backlight_down.sh

/etc/acpi/events/lenovo-4313cto-brightness-up
event=video LCD0 00000086 00000000
action=/etc/acpi/nvidia_backlight_up.sh

ACPI events were determined using acpi_listen.


Alternately, there are .deb packages that install nvidiabl via dkms available from https://github.com/guillaumezin/nvidiabl/downloads . Currently only 4313CTO models have backlight support by default, but it's only a matter of adding PCI IDs and some basic detection stuff. That stuff can be passed when the module is loaded, check the docs for details.

-- 
You received this bug notification because you are a member of Ubuntu-X,
which is subscribed to nvidia-graphics-drivers in Ubuntu.
https://bugs.launchpad.net/bugs/562005

Title:
  Backlight controls of laptops with NVIDIA NVS and Quadro FX 880M GPUs
  no longer function while using proprietary drivers

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/562005/+subscriptions