Comment 116 for bug 191137

The additional debug messages were enough to pinpoint the root-cause of the issue and I had a proof-of-concept patch succeed in fixing the issue last thing yesterday.

Today I worked through the commit logs from mainline and located the two commits that fix the issue in later kernels. I built and tested the kernel with those commit patches applied and couldn't provoke the bug.
Then, reviewing the comments on this bug, I realised that Stefan had referred to the same two commits on 9th July but, because there was no explicit link to a test kernel in his comment, I'd somehow overlooked it and not tried them.

I've currently got my PPA building kernel packages with the patches applied so that others can test the kernel easily. If/when the builds are complete please test the kernel package by adding my PPA to your apt sources:

$ sudo su
$ echo "deb http://ppa.launchpad.net/intuitivenipple/ubuntu hardy main" > /etc/apt/sources.list.d/intuitivenipple-ppa.list
$ apt-get update
$ exit

Update Manager should now discover the package and offer it for installation.

In case the PPA builds fail (kernel-builds are still a dark art!) I'm also building all binary packages. Once built they will be found at http://tjworld.net/ubuntu/bugs/lp191137/

For reference, the fix (if it solves everyone else's problems too) is to cherry-pick the commits:

b3b233c7d948a5f55185fb5a1b248157b948a1e5 Thu Jan 10 20:50:12 2008 -0500 ACPI: EC: Some hardware requires burst mode to operate properly
3e71a87d03055de0b8c8e42aba758ee6494af083 Thu Jan 10 20:49:14 2008 -0500 ACPI: EC: Do the byte access with a fast path

I was trying to figure out why they didn't get into the ubuntu-hardy tree since according to the logs there were several pulls from upstream after the commit date.

Please report your experiences with this test kernel package.