[Karmic] SRU: Enable backlight control on certain laptops

Stefan Bader stefan.bader at canonical.com
Mon Aug 31 13:55:59 UTC 2009

SRU justification:

Impact: Same problem as for current Jaunty: acpi checks for video devices by 
looking for certain methods but some broken BIOSes only define a subset of 
this. Some even do this only for a few of the multiple definitions (one is 
there for each potential hardware variation), so those machines had backlight 
control before Linux verified the PCI ID to be present.

Fix: The following patch was sent upstream and ACKed, but not yet pulled into 
the kernel. Likely this takes until 2.6.32.

Testcase: Tested by the reporters against a patched Jaunty kernel. Without the 
changes there is no backlight control. With it there is.

When all other means of communication fail, try words!

-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-acpi-video-Loosen-strictness-of-video-bus-detectio.patch
Type: text/x-diff
Size: 1989 bytes
Desc: not available
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20090831/9f38c9b6/attachment.patch>

More information about the kernel-team mailing list