[tulip] Problem with tulip, 2.4.0test kernel

[Donald Becker]

On Mon, 15 Jan 2001, Jonathan Earle wrote:

> Thanks for the tip regarding the options line!  I added "options tulip
> options=5,5,5,5" to the modules.conf on the two boxes in question, and now
> dmesg will show:
> 
> eth1: Using user-specified media 100baseTx-FD.
> eth2: Using user-specified media 100baseTx-FD.
> eth3: Using user-specified media 100baseTx-FD.
> eth4: Using user-specified media 100baseTx-FD.     
> 
> >From a cold boot, I now have all four ports operating.  I didn't realize
> that all four had to be set individually, although it's fairly obvious now.
> Hindsight is always 20/20.
> 
> Is it fair to say that the 2.4.0 driver has problems auto-negotiating or is
> the problem I saw symptomatic of something else?

Correct.
The 2.4.0 obviously driver doesn't have the 21143 autonegotiation code
quite right.  It's tricky to do correctly, especially with a board that
uses the general purpose pins to select the power to SYM transceiver
chip and light the correct LEDs.  The driver sometime must use the
information in the EEPROM media table, and other times should just guess
what to do.

Autonegotiation in SYM mode is complicated by the illogical layout and
changing mode of the 21143 control bits.  For instance the FullDuplex
bit in CSR6 used to mean that the chip was in full duplex mode.  But in
the 21143 it sets the 10baseT-FDX bit in the NWay capability word.  All
of the other advertised bits are in CSR14!


> Also, I infer that this card does not use MII registers, but emulates them
> instead.  What does that ultimately mean?  What does this card use in place
> of those registers?

It uses a SYM (Symbol mode) transceiver instead of a MII transceiver.
SYM transceivers are an older type, simpler and slightly less
expensive.  But they were not designed with autonegotiation or hardware
diagnostics in mind, and thus are a pain to deal with.

The 21143 is pretty much the only chip that still ships with SYM
transceiver support.  Most modern chips have an on-chip transceiver with
MII-like management registers.

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
Annapolis MD 21403			410-990-9993