fxp entering promiscuous mode causing link to bounce

[YongHyeon PYUN]

On Sat, Mar 17, 2012 at 09:53:31PM -0400, Mike Tancsa wrote:
> On 3/17/2012 6:58 PM, YongHyeon PYUN wrote:
> > On Fri, Mar 16, 2012 at 04:49:54PM -0400, Mike Tancsa wrote:
> >>
> >> tcpdump -ni fxp0 -c 20
> >>
> >> fxp0: link state changed to DOWN
> >> fxp0: promiscuous mode enabled
> >> fxp0: link state changed to UP
> >> fxp0: link state changed to DOWN
> >> fxp0: promiscuous mode disabled
> >> fxp0: link state changed to UP
> >>
> >> I verified it on 2 different boxes. Is there a way to prevent this from happening ?
> >>
> > 
> > It looks like a regression introduced in flow control support.
> 
> 
> Thanks very much, that indeed did fix it!!
> 
> 
> 0(smtp1)# patch < fxp.p
> Hmm...  Looks like a unified diff to me...
> The text leading up to this was:
> --------------------------
> |Index: sys/dev/fxp/if_fxp.c
> |===================================================================
> |--- sys/dev/fxp/if_fxp.c       (revision 233076)
> |+++ sys/dev/fxp/if_fxp.c       (working copy)
> --------------------------
> Patching file sys/dev/fxp/if_fxp.c using Plan A...
> Hunk #1 succeeded at 900 (offset -2 lines).
> Hunk #2 succeeded at 2808 (offset -2 lines).
> Hunk #3 succeeded at 2914 (offset -2 lines).
> 
> 
> fxp0: promiscuous mode enabled
> fxp0: promiscuous mode disabled
> 
> ... and not bounced link/dropped packets.

Thanks for testing. Committed in r233158.
fxp(4) controllers require controller reinitialization for
promiscuous mode change so it's normal to miss packets during that
transition.  fxp(4) controllers have many limitation and this is
one of them.