[vortex] Re: [3com905b freeze Alpha SMP 2.4.2] FullDuplex issue ?

[Bogdan Costescu]

On Wed, 2 May 2001, Pekka Savola wrote:

> The 100/FD forcing was done with 'options=4 full_duplex=1'.  Then the
> output is as above.  But shouldn't mii-diag -p 24 still work?

That's the problem. options=4 disables the MII/NWAY code, so that a MII
transceiver is not looked for. mii-diag gets bogus data afterwards.

> However, there appears to be a problem with the driver with this specific
> chipset; if I change the forcing to 'options=8 full_duplex=1' as is
> proper, the mii-diag shows good:

Yes, options=8 enables NWAY support. However, in this case, full_duplex is
invalid as autonegotiation implies "no forcing". I guess that this
combination of options should be forbiden.

> The switch (Nortel Networks) is configured to 100/FD static.

That's the second part of the problem. The autonegotiation only works if
_both_ ends of the connection use it. So you can either use
autonegotiation at both ends or force both ends. If you would turn on
autonegotiation on the switch and insmod 3c59x without any options, things
should work as expected.

[ I have here a BayStack 350/24 which works flawlesly with 905B/C cards. ]

> [Yeah, I know 100/FD forcing is bad; but I can't help it here :-( ]

If the switch settings cannot be changed (for administrative or whatever
reason), you're stuck. But then why do you need mii-diag to work ? All it
can report would be 100/FD.

> The difference here is that when you change to 'options=8 full_duplex=1',
> it actually _works_ too.
> ...
>    Link status: previously broken, but now reestablished.
>  Your link partner is generating 100baseTx link beat  (no
> autonegotiation).

No ideea why... this transceiver seems to work even when the remore end is
not autonegotiating.

> I took this as expected behaviour :/.

8-)

> I'm sorry for creating fuss with wrong configuration.

No problem! You're not the first one... 8-)

Sincerely,

Bogdan Costescu

IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen
Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY
Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868
E-mail: Bogdan.Costescu@IWR.Uni-Heidelberg.De