[Jaunty] Brightness to minimum, cannot change (Lenovo 3000 C200)

[damip]

Hello,
I'm running an up-to-date version of Jaunty on my laptop, a Lenovo 3000 C200.
However, for few days now, the brightness of the screen is minimal, and I cannot change it, which is sometimes really annoying.
The brightness hotkeys do not work (nothing happens when pressed), the brightness settings of gnome are simply ignored (without any error message), and the Brightness Applet says it cannot get the brightness of my laptop, and it cannot set it as well.
Please tell me which informations you need, because I don't know what to send.
Thanks.

[Dan Trevino (dantrevino)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please attach your X server configuration file (/etc/X11/xorg.conf) and X server log file (/var/log/Xorg.0.log) to the bug report as individual uncompressed file attachments using the "Attachment:" box below. Could you please also try to run without any /etc/X11/xorg.conf and let Xorg autodetect your display and video card? Please also attach the /var/log/Xorg.0.log from this attempt. Thanks in advance.

Dan

[damip (damipator)]

Hello,
there are the files.
However, the problem persists.

[damip (damipator)]

Hello,
I've updated my system one hour ago, but the problem is still there and it really affects the laptop usability, I cannot read anything when there is even low sunlight.

As there are still no fixes, I decided to try some workarounds.
There is more information.

All the following commands are done as root.

================================
dbus-send --system --print-reply --dest=org.freedesktop.Hal \
/org/freedesktop/Hal/devices/acpi_lcd \
org.freedesktop.Hal.Device.LaptopPanel.SetBrightness \
int32:2

returns :
Error org.freedesktop.DBus.Error.UnknownMethod: Method "SetBrightness" with signature "i" on interface "org.freedesktop.Hal.Device.LaptopPanel" doesn't exist
================================

================================
Killing hald and launching it as follows :
/usr/sbin/hald --daemon=no --verbose=yes

shows, when trying to change brightness :
18:11:38.964 [D] hald_dbus.c:3197: udi=/org/freedesktop/Hal/devices/computer_logicaldev_input_0
[12229]: 18:11:38.966 [D] addon-acpi.c:201: event is 'video LCD 00000086 00000000

...but the brightness still stays minimal.
================================

================================
echo 3 > /proc/acpi/video/GFX0/LCD/brightness
bash: echo: write error: Invalid argument
================================

================================
cat /proc/acpi/video/GFX0/LCD/brightness
<not supported>
================================

The folder /sys/class/backlight/ is empty.

I've also tried omnibook, as some people suggest when facing similar problems, but it doesn't work too.

Brightness-applet dispays a tooltip saying "Cannot get laptop panel brightness" and, when launched with debugging, says that power-manager says that the brightness is not supported on my laptop.

It's sad because brightness worked correctly with previous releases of ubuntu and even with jaunty, relatively, at the beginning.
Everything works perfectly under Windows XP.

I don't know what to add. I've tried all the stuff I know. The bug is still there.
Please tell me if you need any more information.

[Martin Pitt (pitti)]

If you upgraded, you hould still have some older kernels installed. If you boot and press "esc" you get into the boot menu ("grub") where you can select older kernels. Start with 2.6.27-something, which is the Ubuntu 8.10 Linux kernel, check if it works again, and if so, please work your way upwards to the latest Jaunty kernel and check where it breaks.

If even the Intrepid kernel does not work any more, then it is a regression in a different component. In this case, can you please check https://wiki.ubuntu.com/Hotkeys/Troubleshooting whether the brightness keys produce a proper keyboard event? (you should see it in "xev" already).

[damip (damipator)]

Hello,
I doesn't break anymore, with any installed kernel.
However, when it was broken, the problem appeared with all the kernels in
the list (I've tried them all), even with the kernels which were working
well with brightness before the bug.

[Martin Pitt (pitti)]

OK, great to hear that it's fixed now. Thanks for your report!