Subject: Re: DECchip 21143 and the tlp driver.
To: Brad Spencer <>
From: Manuel Bouyer <>
List: current-users
Date: 10/29/1999 10:44:03
On Thu, Oct 28, 1999 at 11:00:30PM -0400, Brad Spencer wrote:
> I have a 4 port D-LINK ethernet card, model DFE-570TX.  This card has 4
> 21143 ethernet chips on it.  I have some of questions that I am hoping
> that someone can answer:
> 1) The tlp driver appears to have some support for the 21142 chip and
> perhaps some 21143 support, however, that driver complains that it can't
> handle my card.  The last thing printed was a line something like:
> 	DECchip 21143 Ethernet, pass 4.1
> I suspect that it might not be too bad to get this working, but it is
> unclear to me what is required.  [before I started I made sure I had
> 'options TLP_MATCH_ ...' in my kernel config.  I have another machine with
> a 21041 in it and the tlp driver works great there].

As far as I know the 21143 is not supported yet by tlp. Jason could certainly
add precisions about this :)

> 2) Falling back on the de driver...  I have a 10/100 ethernet switch that
> can do full duplex and the auto probe finds that it is connected to a
> 100Mbits full duplex port, as expected.  However, it appears that an
> output error is generated [or at least recorded] for every every packet
> sent down the wire.  Slightly annoying, but I don't know if this is
> significant.

What swicth do you have ?
I have a cisco 10/100 switch I don't have this behavior under 1.4.x.
Maybe your board and switch dissagree on the half/full duplex settings ?

> 3) The de driver does not appear to be able to change the media type
> properly on my card.  Is this a known problem??  That is, an 'ifconfig de0
> media 10baset' does not appear to set the media to 10 base twisted pair,
> although it claims to have set the media.  Likewise for full and half
> duplex.  [At least the switches blinking lights do not seem to indicate a
> change in media type].

This happens sometimes, it's because your switch doesn't restart
autonegotiation. Off/On on the switch may be a way to force it to
renegotiate :)

> 4) The de driver reports stuff like this before calming down:
> de0: abnormal interrupt: transmit underflow (raising TX threshold to 128|512)
> de0: abnormal interrupt: transmit underflow (raising TX threshold to 160|1024)
> de0: abnormal interrupt: transmit underflow (switching to store-and-forward mode)
> I really don't know what the above indicates, as such...  except to note
> that it is complaints about sending packets...

Hal Murray already explained this.

Manuel Bouyer, LIP6, Universite Paris VI.