Please SRU woraround for bug #276990

[Thomas Jaeger]

There is a known kernel panic in the iwlagn module of the 2.6.27 kernel
related to 802.11n network traffic:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/276990

Currently users are told in the release notes to install the
ubuntu-backports-modules package, which is less than ideal for the
following reasons:

* Very few people actually read the release notes, so they won't know
that they should install the package
* The problem is extremely hard to track down for an average user due to
the fact that the kernel panic is only indicated by blinking LED lights
with no messages displayed on the screen
* The bug report is difficult to find on launchpad since its importance
is set to undecided meaning that it only shows up at the end of the bug
list.
* ubuntu-backports-modules is just a random daily snapshot of
compat-wireless that was never intended by the developers to be used
productively.  In particular, its iwlagn module triggers lots of kernel
warnings not present in the original 2.6.27 module.
* people experiencing random system freezes might easily get the
impression that ubuntu in particular or linux in general is unstable

Given all these factors, I think it is important that the workaround for
this problem that has been adopted upstream be pulled in as soon as
possible.  The relevant commit is

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=55d6a3cd0cc85ed90c39cf32e16f622bd003117b

The patch is clearly safe, turning a kernel panic into a warning and it
is actually contained in the compat-wireless snapshot used
ubuntu-backports-modules packages, so it has already gotten a fair
amount of testing.  It has also been tested by several people as a
stand-alone module in the bug report referenced above.

Thank you