Comment 24 for bug 462939

If anyone gets a chance to test this with lucid, you should add the tag 'lucid-kms' so it gets on the kernel team's radar. It's not likely to get on their list if it is only tested against karmic.

Be aware though that kms got blacklisted for i855 but quite a few people have reported this isn't working for them, so you will need to force kms on by passing the kernel option i915.radeon=1 from grub.