I had a look at the data provided. It seems that before the patch, brightness was controlled by the acer-wmi driver (as the definition provides only _DOD and would therefor have been ignored). Now the acpi video driver looks at the video device but seems to get an invalid brightness value (which strikingly looks like a date to me).
[ 3.698698] [Firmware Bug]: ACPI(Z00P) defines _DOD but not _DOS [ 4.232085] ACPI Error: Current brightness invalid 20090521 video-538 [ 4.232263] input: Video Bus as /devices/LNXSYSTM:00/device:00/PNP0A08:00/device:0f/device:10/input/input6 [ 4.232354] ACPI: Video Device [Z00P] (multi-head: yes rom: no post: no) [ 13.325165] acer-wmi: Brightness must be controlled by generic video driver The methods in the BIOS look incorrect to me (it stores x=((b/10)-1) but reads b=((x*10)+1), where b is the brightness value and x the one stored on the ec). But that should normally not result in a value seen in the error message. This needs more investigation. For now, can you try the following: add "acpi_backlight=vendor" to the kernel command line either on boot (which is a bit hard with grub timeout being 0, one needs to press shift quickly) or in /etc/default/grub and calling "sudo update-grub". Does this restore the old functionality? -- Acer Aspire 5520 has backlight broken in Karmic Koala https://bugs.launchpad.net/bugs/428910 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
