[LUCID] Brightness fn keys have no functionality (Toshiba laptops)

[Trent Telfer]

Fn Brightness keys non responsive in Karmic. The keys worked fine 9.04. All other combinations of Fn keys seem to work fine.

This is a similar bug to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/406515 but for Toshiba laptops.

The gnome brightness applet works and is capable of adjusting the brightness.

My system is a Toshiba Satellite A500-00L

Linux 2.6.31-18-generic #55-Ubuntu SMP Fri Jan 8 14:54:52 UTC 2010 x86_64 GNU/Linux
Ubuntu 9.10

[Trent Telfer (unnaturalhigh)]

Some bugs that might have some relationship to the one I am experiencing.

http://bugzilla.kernel.org/show_bug.cgi?id=14506
http://bugzilla.kernel.org/show_bug.cgi?id=15054
http://bugzilla.kernel.org/show_bug.cgi?id=15162

[Trent Telfer (unnaturalhigh)]

This bus is also present in 10.04 LTS. It is sad how long this bug has now existed for without a fix. Little things like this are reasons why my sister went back to windows.

[Unsk1ll3d (ubuntu-only)]

Haha, I solved the Bug!

The ACPI key-scripts seem to echo 0-100 to the following location:
 /proc/acpi/video/GFX0/LCD/brightness

...but that is false! The graphics card on my compaq615 is mounted to /proc/acpi/video/IGFX

Enter this to get a description which kind of values are allowed by the driver:
cat /proc/acpi/video/IGFX/LCD/brightness

Create a test script and test it via sudo:

#!/bin/bash
echo 100 > /proc/acpi/video/IGFX/LCD/brightness

Now I've got my full backlight again =)
If you want to change the backlight of an external monitor, just...
ls -l /proc/acpi/video/IGFX
...to see the "available" Monitors (connectors) of your graphics card.

Cheers!
Chris

[Francesco S. P. (samjack)]

i am on lucid with kernel Linux ubuntu 2.6.31-21-generic #59-Ubuntu SMP and fn+f6/7 for brightness do not work.

i read https://wiki.ubuntu.com/Hotkeys/Troubleshooting

and i discover that udev not recognize keypress but acpi_listen report:

hkey VALZ 00000000 00000140
hkey VALZ 00000001 00000140
hkey VALZ 00000000 00000140
hkey VALZ 00000001 00000140

for fn+f6 and fn+f7

PS sorry for my bad english

[Francesco S. P. (samjack)]

add to my previous post:

sudo /lib/udev/keymap input/event4 > /tmp/orig-map_satellitea50.txt

cat /sys/class/dmi/id/sys_vendor =>
TOSHIBA
cat /sys/class/dmi/id/product_name =>
Satellite A50

[Francesco S. P. (samjack)]

with the kernel 2.6.34 fn keys for brightness work properly, but only with 3 level: low, medium, high.

[Florian Sievers (florian-sievers)]

Try updating to Catalyst 10.5 from ATi/AMD, that solved the problem for me and some others.

[Brad Figg (brad-figg)]

This bug was filed against a series that is no longer supported and so is being marked as Won't Fix. If this issue still exists in a supported series, please file a new bug.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.