[tulip] strange speed&duplex? (accton en 2242)

[Erik Steffl]

Donald Becker wrote:
...
> > # ./mii-diag
> > Using the default interface 'eth0'.
> > Basic registers of MII PHY #1:  1000 786d 0022 5410 01e1 40a1 0005 2801.
> >  Basic mode control register 0x1000: Auto-negotiation enabled.
> >  You have link beat, and everything is working OK.
> >  Your link partner advertised 40a1: 100baseTx 10baseT.
> 
> Your link partner is a half duplex bridged repeater.
> It cannot do full duplex.
> If you force full duplex, you will have very bad performance.
> 
> The new version of 'mii-diag' calculates the speed and duplex for you.
> With the older versions you have to manually interpret the highest
> common capability.

  how do I find out what speed is actually used and whether it's FD or
HD? I checked the docs for mii-diag on scyld.com but it all seems to
refer to capabilities, not the actual settings.

  the link partner is a D-Link DSH-5 hub with switch (dual speed,
10/100Mbps), it says it can operate different speeds on different
ports... it has a EXP-FDX led which is on and description says:
expansion switch full duplex status. I thought it means it operates in
full duplex mode but I guess it only means that up-link (port that can
connect this one to another hub) is capable of FD (or something else,
not sure what expansion port is).

  I have two other computers connected to the same hub, one says it's
half duplex (ms win machine) and the other says:

eth0: RealTek RTL8139 Fast Ethernet at 0xc884b000, 00:50:ba:40:62:18,
IRQ 11
eth0:  Identified 8139 chip type 'RTL-8139B'
eth0: Setting full-duplex based on MII #32 link partner ability of 41e1.

  how come? it's a kernel driver (the driver from scyld does not work
with 2.4.x kernels), I used the diag program from scyld anyway and it
also says it's full duplex (capability, not sure what the actual setting
are):

jojda:~...diag/mii-diag>./mii-diag
Using the default interface 'eth0'.
Basic registers of MII PHY #32:  1100 782d 0000 0000 01e1 41e1 0001
0000.
 Basic mode control register 0x1100: Auto-negotiation enabled.
 You have link beat, and everything is working OK.
 Your link partner advertised 41e1: 100baseTx-FD 100baseTx 10baseT-FD
10baseT.

  I guess I need a different hub/switch - how do I find out whether it's
full duplex (on all ports)? I checked the docs again and it does not
mention whether ist's FD or HD anywhere - does it mean that unless it
specifically mentions FD I should assume it's HD only? Any pointers on
how to pick up 100Mpbs FD hub/switch appreciated...

> > # ./tulip-diag
> > tulip-diag.c:v2.07 3/31/2001 Donald Becker (becker@scyld.com)
> >  http://www.scyld.com/diag/index.html
> > Index #1: Found a Accton EN1217/EN2242 (ADMtek Comet) adapter at 0x1c00.
> >  Comet duplex is reported in the MII status registers.
> 
> Take careful note of this message!

  why? what does it mean? What does Comet duplex mean?

> >   or '-m' or '-mm' to show MII management registers.

  thanks a lot for response,

	erik