Re: iwn0 driver: status

[Brett Lymn <blymn%baesystems.com.au@localhost>]

On Thu, Sep 04, 2008 at 06:26:44PM +0200, Marcin M. Jessa wrote:
> >
> >This is what gets written to console after system crash:
> >
> >fatal page fault in supervisor mode
> >trap type 6 code eip c03f8856 cs 8 eflags 210282cr2 4 ilevel 6
> >panic: trap
> >syncing disks... iwn0: device timeout
> >
> >
> >
> >I'm on x86, NetBSD 4.99.72 compiled Tue Sep 2 22:46:32 CEST 2008
> >
> 

Any chance you can build a kernel with ddb support and get a
backtrace?  For what it is worth - iwn may be an innocent victim here.

> If this helps, I also changed the value of MTU to 1460 and started 
> downloading a torrent. Then following message was written to console 
> (about 10 times) before the system crashed with the same error message:
> 
> iwn0: discarding oversize frame (len=1514)
> 
> The value of len was variable from 1494 to 1514 (always bigger than the 
> size of MTU and usually bigger than 1500).
> 

Well, yes, that is expected.  If you have reduced your MTU then you
probably should clamp the MSS as well otherwise the sending end will
send back a packet that fits it's MTU.  If icmp is not being blocked
the sender should received a "this packet is too large" icmp back from
your end and reduce the MTU so seeing a couple of those messages would
not be bad - if you saw great streams of them then something is wrong.

-- 
Brett Lymn
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