Lenovo laptop brightness control problems (3000 100N and SL300)

[Piotr Czachur]

Ubuntu: 9.04
Laptop: Lenovo 3000 N100
uname: Linux lestaro 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux

Problems:
a) After upgrade to 9.04 jaunty laptop brightness cannot be adjusted properly:
* Fn + brightness+ switch between dark and less darker (look)
* Fn + brightness- turns screen darked, only one step available
b) Brightness applet is almost unusable: screen is heavy flickering all the time when adjusting brightness, just like mentioned in Bug #368506.

To fix: brigthness adjusting via Fn keys and via brightness apllet.

[Amol (amolmodi)]

I have the same problem with the Fn brightness keys on my Lenovo SL300. The brightness applet, however, adjusts the brightness just fine, even though it can't actually get the current brightness.

[Amol (amolmodi)]

It's worth noting my SL300 has an Nvidia Geforce 9300M, and I'm using the Nvidia driver, as opposed to Piotr, who seems to have an Intel GPU. This might account for why the brightness applet works for me.

[Piotr Czachur (zimnyx)]

Yeah, you're right - xorg uses Intel driver in my case.

[Scott Howard (showard314)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. There appears to be two issues here:
1) brightness control using Fn keys
2) blinking when using brightness control

We should focus one bug per report, and we should focus on "1" above since "2" has been reported by someone else using an Intel driver (bug #368946).

The first issue that you reported is one that should be reproducible with the live environment of the Desktop CD of the development release - Karmic Koala. It would help us greatly if you could test with it so we can work on getting it fixed in the next release of Ubuntu. You can find out more about the development release at http://www.ubuntu.com/testing/. Thanks again and we appreciate your help.

[Piotr Czachur (zimnyx)]

I've just lunched "Karmin Koala Alpha 2" on my laptop, and problem is still there. When pressing brightness controll keys gnome brightness progress bar doesn't move, and screen brightnes changes for a moment, and screen always gets dimmed. If you need further info I'm here.

[Scott Howard (showard314)]

Thanks for testing and confirming.

Here's some stuff to try:
(from bug #399675)
A workaround is unloading/reloading the "video" kernel module, but
after this the brightness-changing-OSD doesn't appear anymore and I
guess there may be other issues, at least it's not the elegant way ;)

@amol (the SL300 owner):
see the following links. If you can try their workarounds, post back here.
http://ubuntuforums.org/showthread.php?t=1137682&highlight=sl500+brightness
http://gianlucamagalotti.wordpress.com/2009/02/16/lenovo-thinkpad-sl-series-hotkeys/
http://ubuntuforums.org/showthread.php?t=1150002

If any of these work, it looks like a kernel problem (acpi), so we can assign to linux (Ubuntu).

[Scott Howard (showard314)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 351586, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find, and if this bug remains after the fixes have all been released and tested, please reopen this bug by removing the "duplicate" tag.