Workaround for "fatal firmware error" iwn(4) problem.

[David Wolfskill]

On Fri, May 16, 2014 at 08:06:02PM +0200, Edward Tomasz Napiera?a wrote:
> I've started using FreeBSD laptop and iwn(4) failing at random moments
> like this...
> 
> May 16 17:11:54 brick kernel: iwn0: iwn_intr: fatal firmware error
> May 16 17:11:54 brick kernel: firmware error log:
> May 16 17:11:54 brick kernel: error type      = "NMI_INTERRUPT_WDG" (0x00000004)
> ...
> 
> ... has been driving me crazy, so I wrote a workaround.  The patch
> can be found here:
> 
> http://people.freebsd.org/~trasz/iwn.diff
> 
> I think it's too ugly to commit it as is (I'd never release crap like this,
> but I know nothing about WiFi and iwn(4) in particular, so I feel justified),
> but feedback is still welcome.

On Fri, May 16, 2014 at 08:16:01PM +0200, Edward Tomasz Napiera?a wrote:
> ...
> > For which branch?
> 
> Ah, forgot about that.  11-HEAD.

So I've been running head/i386 with the above-cited patch for about 1.75
hrs. now -- by which time I would normally expect to have seen my
network connection have dropped -- and it's been quite steady, even
through listening to a streaming audio program for about an hour.

I'm hoping that this at least helps indicate what might be going wrong
(without the patch).

For reference (in somewhat more detail): I had built:

FreeBSD 11.0-CURRENT #1250  r266209M/266213:1100021: Fri May 16 06:24:39 PDT 2014     root at g1-252.catwhisker.org:/common/S4/obj/usr/src/sys/CANARY  i386

yesterday (on my "head" slice on this laptop); this morning, I
updated the src working copy to r266297 without incident (save for
the occasional, and expected, dropping of the network connection
on occasion).  I then rebooted, and verified that

FreeBSD 11.0-CURRENT #1251  r266297M/266298:1100021: Sat May 17 09:17:53 PDT 2014     root at g1-252.catwhisker.org:/common/S4/obj/usr/src/sys/CANARY  i386

seemed to function pretty much the same (which it did).

I then "cloned" the file systems on my head slice to another slice,
used "svn patch" to apply the patch:

Script started on Sat May 17 09:53:48 2014
command: svn patch tmp/iwn.diff /usr/src
U         /usr/src/sys/dev/iwn/if_iwn.c

Script done on Sat May 17 09:53:48 2014

then ran "cd /usr/src && make -DNOCLEAN -j4 kernel"; the result was:

FreeBSD 11.0-CURRENT #1252  r266297M/266298:1100021: Sat May 17 09:56:18 PDT 2014     root at g1-252.catwhisker.org:/common/S2/obj/usr/src/sys/CANARY  i386

(which is what I've been running for almost 2 hrs. now).

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Taliban: Evil cowards with guns afraid of truth from a 14-year old girl.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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