[patch] re(4) problems on networks with disabled autonegotiation "solver" (WAS: Juniper e3k with ports limitied to...) -- REQUEST FOR REVIEW

[Pyun YongHyeon]

On Wed, Jan 12, 2011 at 12:59:58PM -0800, Artem Belevich wrote:
> 2011/1/12 Lev Serebryakov <lev at serebryakov.spb.ru>:
> > Hello, Freebsd-net.
> >
> > ?Thanks to Pyun YongHyeon, who point me at fact, that rgephy(4) used
> > with re(4) does autonegotiation always and all other, who helps me
> > diagnose problem!
> >
> > ?I've prepared patch, which adds tunable/sysctl for rgephy(4) which
> > allows not to sue autonegotiation by this PHY (at user responsibility,
> > as here is PHYs which CAN NOT live without autonegotiation). It is OFF
> > by default, and in such case behavior of driver IS NOT CHANGED.
> >
> > ?But if it is set ON (non-zero value) before "media / mediopt"
> > changes via "ifconfig" autonegotiation IS NOT set with 10/100Mbit
> > settings.
> >
> > ?I've documented this new tunable in re(4) manpage, as here is no
> > rgephy(4) manpage.
> 
> I wonder if we could make autonegotiation another media option.
> This may solve the problem at hand in a more generic way.
> 
> In case someone specifies speed/duplex settings but want
> autonegotiation on, we can advertise only that particular speed/duplex
> capability (as opposed to advertising everything we support). This
> would force remote end to either establish the link with the
> parameters we want or keep the link down which would be better than
> keeping the link up with mismatched duplex settings.
> 

Yeah, that would be good option. However, it's not trivial to
implement these things on all PHY drivers. Some PHY hardwares do
not have a capability which can tell it successfully resolved
speed/duplex with manual media configuration.