Subject: Re: Tulip driver (if_de) and MII
To: None <>
From: Dave Sainty <>
List: tech-net
Date: 03/01/2000 01:31:06
"Jonas Larsson" writes:

> Hi all. I'm having trouble getting the de driver work properly
> with network cards from D-Link. The model is a DFE-570TX with
> a PHY from National S. (DP83843). It's a quad card with 21143-TD.
> Also single cards have the same behaviour.
>    Running the cards in full-duplex gives very poor performance.
>    Below are two tests ran with netperf. One is a direct connection
>    with a cross-over (which gives full-duplex as above) and one
>    is through a hub witch forces the PHYs into half-duplex.

The if_de driver didn't really play the MII game properly.  If you're
running current, use the newer 'tlp' driver, which is far more likely
to give good results.  It uses the mii subsystem too.

> > That's the standard symptom when one end is running in full-duplex 
> > mode and the other is half-duplex. 
> But even if I choose full-duplex on both ends I get the lousy performance.

I think you'll find that the MII is not really in full duplex mode,
even when the driver claims it is.