Subject: Re: ifmedia on fxp: can ifmedia defeat NWAY and force 10baseT?
To: None <thorpej@nas.nasa.gov>
From: Jon Lindgren <net/a28043/jlindgren@espus.com>
List: tech-kern
Date: 10/26/1999 06:48:56
Jason R. Thorpe <thorpej@nas.nasa.gov> wrote:

> > I have an fxp (EEPro 100+ client) connected to a NetGear 10/100
> > autosense hub. I'm trying to use ifconfig's ifmedia support to
> > throttle the card down to 10Mbit/sec.  The lights on the NetGear
> > still say the card is at 100Mbit, even though ifconfig says the
> > media type is now 10baseT.
>
> ...actually, the hub's lights say the hub is using 100TX for that
> port; they say nothing about the link partner (except the "link"
> light, if your hub has one).
>
> > Is this a bug in the MII code, or is what I'm trying to do not
> > supported by the hardware?
>
> It's more likely a bug in the hub's firmware.  When you switch from
> 100 to 10, the 100 link goes into fail state, and the hub should
> detect this and restart Nway; the PHY on the card, when hard-wired
> to 10T, advertises only 10T capability in its Nway code word.
>
> Anyhow, the hub probably isn't restarting Nway.  This may be due to the
> hub not properly detecting link fail.  Try unplugging the wire and
> plugging
> it back in.

Actually, I had the same problem.  I had a de0 and an fxp0 in the same
machine, and connecting them to a netgear 10/100 hub caused problems with
fxp0, while de0 was just fine.  Trying a separate 10/100 switch resulted
in the same problems with fxp0, while the de0 card worked just
fine.  Replacing fxp0 with an epic resulted in everything AOK... it was
just the fxp card which was giving me problems.

In my situation, the fxp0 card appeared to be in 100 FD mode (according to
the hub and the card's leds) but even after numerous ifconfig attempts it
insisted it was on the 10baseT media.  All during this, "fxp0: device
timeout" or such messages were generated about every 10 seconds (sorry -
it was two days ago and I've forgotten the exact message).

-Jon Lindgren
 "Hopefully me employer has gotten the message, and this message has no
markup."