[RFC] Moving Intrepid to 2.6.27 kernel

Matt Zimmerman mdz at ubuntu.com
Tue Aug 26 14:42:05 BST 2008

On Sun, Aug 24, 2008 at 10:51:46PM -0400, Ben Collins wrote:
> Matt Zimmerman wrote:
> > Where can I find the summary and log of the meeting?
> I can put one together.

That would be much appreciated.  This should be standard practice for IRC

> > I was in meetings all week and didn't see this until now.  Mario has raised
> > a concern in this thread which I think needs to be addressed.  I also have
> > the following questions:
> I've tested LRM, and it compiles fine. I've tested at least broadcom's 
> driver.


> > What are the known regressions from 2.6.26 to 2.6.27?
> I've looked at the list of known regressions from upstream, and the 
> critical/important ones have been addressed or don't affect us.

Would you mind sharing the list and your analysis?

> > Which systems has 2.6.27 been tested on?  What test plan was followed?
> I've tested 32-bit and 64-bit on Xeon, 4+ laptops and a few of Intel's 
> SDP's. Tim has done further testing. I know the server team has been 
> checking the 2.6.27 kernels as well. In addition, I've had feedback from 
> more than a dozen others that have been using the 2.6.27 kernels on 
> various platforms because of fixes major problems for them over 2.6.26.

What's involved in these tests?  Is it something more than checking that it
still boots?

> > In which areas are further regressions to be expected in 2.6.27 (which parts
> > of the kernel have changed in the most significant ways)?
> Alsa and wireless are the major areas. In 2.6.26 there were major 
> updates to RTC, which seem to have settled now in 2.6.27. Alsa and 
> wireless are major improvements over 2.6.26.
> The problem with 2.6.26 is that wireless updates there are causing major 
> regressions in suspend/resume, which as far as I'm concerned is a 
> showstopper in itself. 2.6.27 fixes these issues.
> Also included in the wireless update is ath5k/ath9k updates, which could 
> make madwifi unneeded, stomping out one lrm driver. There's also a new 
> iwlagn driver and iwl5k driver, bringing better support for newer Intel 
> wireless cards, including 11n support for 4965 (these new drivers 
> require the new wireless stack, so we can't just grab the drivers).
> Updating to Alsa 1.0.17 is a must-have for intrepid due to various 
> driver updates. If we release with 1.0.16 (which is in 2.6.26) we wont 
> be supporting a lot of new hardware.

I think I understand all of the reasons why moving to 2.6.27 would be
desirable.  What I don't think we've covered well enough are the risks of
doing so.

> > What were the results of certification testing with 2.6.27?
> No results that I know of. We have no way to do one-off certification 
> testing that I'm aware of.

All you should need to provide is an ISO.  It should be simple enough to
swap in a new kernel for test purposes.

 - mdz

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