Comment 78 for bug 333386
Revision history for this message
| Stefan Bader (smb) wrote Re: Cannot change brightness with 2.6.27-11+ kernel | #78 |
© 2004
Canonical Ltd.
•
Terms of use
•
Data privacy
•
Contact Launchpad Support
•
Blog
•
Careers
•
System status
•
0e1f616
(Get the code!)
Hm, with that info I understand what is going on. But I cannot see how Linux could safely make this working. The problem is that graphic devices are detected by certain methods in the ACPI BIOS. From all available alternatives only _DOS and _DOD methods are defined for the GFX0 device. So far, so good. Unfortunately the GFX0 definition contains an _ADR element that claims the related PCI device would be device number 2. However the dmesg shows that this should be device number 1 (you can verify that with "lspci|grep 00:02.0"). The code to check for a physical pci device being present was added around the time when brightness controll stopped working for you.
Though it might be possible to add code to skip this test to Jaunty, this just would hit you again with Karmic and later. I would have provided a modified DSDT to test but for some reason the acpi compiler is not able to recompile the disassembled DSDT.
On the Acer site I just saw that there is an updated BIOS available (1.14 dated 2009/06/03). Unfortunately I saw nowhere what exactly it should change but it might be worth a try.