[vortex] Problems detecting 100Mbps with 3c59x (Vortex)

CJ Kucera pez@apocalyptech.com
Mon Dec 30 14:56:02 2002


On Mon, Dec 30, 2002 at 02:35:05PM -0500, Donald Becker wrote:
> First: do not force full duplex!
> 
> When your switch allows forcing the setting, you have a long-term
> network administration problem.
> When your switch cannot be set, you have an immediate bug.

Hm...  I had figured since my other ethernet cards had autodetected
100baseTx-FD, that it was a viable mode for me to be using.  I presume
from when you said "Note that this is required for the 3c595 and 3c590
boards" you mean that autodetection is something that just isn't
possible with the 3c595?  If you take a look at the mii-diag output
from one of my other machines which is working at 100Mpbs it says
that it's autonegotiated the full duplex itself...

> > >   Manufacture date (MM/DD/YYYY) 6/5/1996, division 6, product BU.
> 
> I don't recommend using an old 590 series card if you care about
> performance.
> Even a rtl8139 will have far better performance.

Heh.  Yeah, I figured they'd probably not be great, but they have the
distinct advantage of being the cards I happen to already own.  :)
Still, the 100Mbps mode on the 3c595 should do better than the 10Mbps,
right?  Or is the difference between the two on the 3c595 negligible?

> > So there's definitely some kind of problem there.  Running
> > "vortex-diag -aef", I notice that it gives me conflicting kinds of
> > transceivers:
> 
> What is confliciting?
> The part has both 100baseTx and 10baseT transceiver connections.
> It defaults to 10baseT.

I was referring to the differences between these two lines:
> Transceiver type in use:  100baseTX.
and
>  Transceiver selection: 10baseT.

Looking at it again, though, I suppose that the second line is grouped
under the "EEPROM settings," which I now presume are just the defaults.
So nevermind about that one...

> >   3) At any rate, why isn't the proper speed of the network being
> >      autodetected by *either* of the drivers?  The only way I've been able
> >      to get things running properly is by forcing the options.
> 
> The '10baseT' setting is correct -- the driver detects the 10baseT link
> beat from the switch (autonegotiation takes place on the 10baseT link
> signal) and remains at 10Mbps.  If you had a 100baseTx repeater, or
> 100baseTx only switch, the 3c595 would have switch to 100baseTx (half
> duplex).

So, just to clarify, on a 10/100 switch, the 3c595 will *always* go with
10 as opposed to 100?

> This is accurate.
> 
> Note that you can also use
>    mii-diag -F 100baseTx

Yeah, I had tried that before using the old driver, but nothing seemed
to change when I did so . . .

> > >  You have link beat, and everything is working OK.
> > >    This transceiver is capable of  100baseTx-FD 100baseTx 10baseT-FD 10baseT.
> > >    Unable to perform Auto-negotiation, negotiation not complete.
> 
> Pay attention to that last line.

I suppose I was more curious as to *why* the autonegotiation doesn't
happen.  Is it just a limitation of the 3c595?  Running "mii-diag -v"
on a working machine yields:

> The autonegotiated media type is 100baseTx-FD.
> ...
>    Link status: established.
>    Capable of  100baseTx-FD 100baseTx 10baseT-FD 10baseT.
>    Able to perform Auto-negotiation, negotiation complete.

Thanks again for your help!

-CJ

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