Ubuntu
alsa-driver package

  1. Bug #568611
  2. Comment #77

Comment 77 for bug 568611

Revision history for this message
Hendy Irawan (ceefour) wrote : Re: Screen brightness control fails on Dell Studio 1558, Lenovo Ideapad Z360

I have installed Kamal's fixed kernel from: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/568611/comments/55

Just installing the kernel doesn't make any effect.

During GRUB, after editing the 'linux...' line and appending 'acpi_backlight=vendor' the backlight works as expected.

THANKS Kamal! Right now my Lenovo Ideapad Z360 laptop is operating at 11.4 W (due to reduced backlight). It's usually 16 W (minimum) up to a max of around 25 W. This fix will definitely save me a lot when I'm away from the AC outlet.

Thanks a lot !!!!!!!!

Some minor things though:
* acpi_backlight=vendor shouldn't be required, however this workaround is MUCH better than not working at all....
* At first login my display was completely black. I thought the fix was not working (and I thought it made the computer unusable) until I pressed increased-brightness and it works. The thing is the brightness control works all the way until 0 (pitch dark). IMHO pitch dark shouldn't be allowed, because we already have the button work that (Fn+F2, which works very well), so the darkest brightness should be "a little bit brighter than pitch dark".
* PLEASE make it into official Ubuntu kernel on next update