Thinkpads Forum

I have been searching all around internet but i can't find any solution for this.

I'm using Debian squeeze (with kernel and some packages from backports).

Most of hardware works fine, however, very important display brightness key combination doesn't.

I also noticed that if laptop is running on battery and than i put it on sleep and wake it up, display's brightness drops down.

Do you have any idea how to control this?

Configuration:
T430, running on nVidia. I believe that rest is not important.

p.s. there are few minor issues with hardware too but this one i can't figure out at all. I'm not very familiar with /sys... hardware config, i believe that this issue could be solved by passing certain values to hardware that way.

Hi,

I presume what you are saying is, when you try to use the Fn+Brightness Key combo, it doesn't work.

If that's the case, please check what kernel version are you running on. If its anything below 3.2, then I guess you'll have to do a lot of tweaking. Try and see if you can install kernel 3.2 or higher and the key combo will work.

I have a Lenovo Z570 Ideapad on which CentOS 6.3 gave the same issue. I just had to go to El Repo and download and install the latest kernel_ml, reboot and I was able to toggle brightness with the function keys. Please try to see if something similar exists for Debian. You could always compile the kernel, but that could take time.

I also tried Ubuntu 12.04. Since it comes shipped with Kernel Version 3.2, the brightness toggle worked right out of the box.

Hope this helps.

thinkpadin wrote:Hi,

I presume what you are saying is, when you try to use the Fn+Brightness Key combo, it doesn't work.

If that's the case, please check what kernel version are you running on. If its anything below 3.2, then I guess you'll have to do a lot of tweaking. Try and see if you can install kernel 3.2 or higher and the key combo will work.

I have a Lenovo Z570 Ideapad on which CentOS 6.3 gave the same issue. I just had to go to El Repo and download and install the latest kernel_ml, reboot and I was able to toggle brightness with the function keys. Please try to see if something similar exists for Debian. You could always compile the kernel, but that could take time.

I also tried Ubuntu 12.04. Since it comes shipped with Kernel Version 3.2, the brightness toggle worked right out of the box.

Hope this helps.

It's 3.2 actually but it's newer hardware so it doesn't work.

I didn't have this issues on older thinkpad.

Hi,

I tried booting off a Ubuntu 12.04 from USB and tried reducing/increasing the brightness from the key combo and it works.

Not able to download Debian as there seems to be some issue with my internet connectivity.

Have you tried any other Linux flavour and checked it?

Otherwise, what you could try is installing the newer version of kernel and I think that should take care of it.

thinkpadin wrote:Hi,

I tried booting off a Ubuntu 12.04 from USB and tried reducing/increasing the brightness from the key combo and it works.

Not able to download Debian as there seems to be some issue with my internet connectivity.

Have you tried any other Linux flavour and checked it?

Otherwise, what you could try is installing the newer version of kernel and I think that should take care of it.

Well, since many things didn't work with 2.6.2 kernel i had to install kernel from backports. So it's 3.2 already.

Thank you for info about ubuntu. I believe there must be work around.

thank you

Hi Nardev,

Ubuntu 12.04.2 is released. Its got Kernel 3.5.

I would suggest you try it. I tried it (booting off of a USB Drive) and it works fine. And So did Ubuntu 12.04.1. Please try that.

thinkpadin wrote:Hi Nardev,

Ubuntu 12.04.2 is released. Its got Kernel 3.5.

I would suggest you try it. I tried it (booting off of a USB Drive) and it works fine. And So did Ubuntu 12.04.1. Please try that.

I will try, thank you.