Replying to myself, really, but two new observations:

> There were no problems in the 2.6-series. The bug occurs at least in the
> Debian kernel versions 3.2.0-1-amd64, 3.0.0-2-amd64, and 3.0.0-1-amd64.

As much as I thought and hoped this was true, it is not. I just had the
problem with 2.6.39, so...

> Do not have it now, if really necessary, will get it next time it occurs
> (which may be a while: I am back to 2.6.39 because I need to get work done).

now I have the dmesg, too. See attachment.

Now that I get this bug on a kernel version I never had it before, I am also
inclined to change my mind: perhaps this is not a regression in the kernel,
but in the iwlwifi firmware? I just updated my iwlwifi-firmwre to 0.35, and if
I still see this, I will go back to ~0.30 to see if that fixes the issue.

Now I wonder: could this be related to linux kernel bug #14141 [1] or other
similar problems that plagued iwlagn (predecessor to iwlwifi) in kernel
versions up to around 2.6.38 or so? It seems both bugs appear in similar
situations: after a little uptime (last case was less than 12 hours!) and
under heavy network traffic.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=14141

Cheers,
Juha

--
-----------------------------------------------
| Juha JÃykkÃ, juhaj@xxxxxx |
| http://www.maths.leeds.ac.uk/~juhaj |
-----------------------------------------------

dmesg.txt
Description: Text document