3c905 won't work

[Donald Becker]

On Thu, 25 Feb 1999, Troels Arvin wrote:

> Subject: Re: 3c905 won't work
> 
> At 13:15 24-02-99 +0100, Marc Roberts <mro@aldoc.nl> wrote:
> >The card
> >is connected to a 3Com Superstack II TX hub at 100Mhz. On the card the
> >10Mbps link indicator is on and the Activity indicator is on all the
> >time.
> 
> I have the same problem with a 905 NIC connecting to a 100 mbit 3com switch.

Ohhh, I would blame the 3Com switch first -- they were notorious for
violating the NWay specs.  The 83840A transceiver on the 905 is the defacto
standard for proper NWay implementations.  The driver doesn't have to do
anything but read and calculate the negotiated duplex.

> I believe that a lot of 905 cards are buggy, but I can't document it - I
> can only say that I have had seriously bad problems with 905's on both
> Linux and Netware (on a Netware server, severe stability problems were
> cured by changing to a dirt-cheap Realtek NIC...). And I know several other
> people who have the same experiences. I a Danish newsgroup, a reseller said
> that close to 5% of their shipped 905's were returned due to problems.

The 905B cards have three different transceiver implementations, all of
which are broken in their own special way.  The regular '905 uses a seperate
transceiver, and is wonderfully stable (but cannot implement Wake-On-LAN or
other special controls because of the seperate transceiver).

> About the 10mbit LED being active:
> Your card's auto-negotiation failed. The (not very elegant) cure: Keep
> connecting/unconnecting the network cable until the card finally
> understands that it's talking to a 100 mbit connection.

Yup, blame the switch.  It's a timing issue that can mitigated with a
firmware upgrade on some switches.  

> There are some 3com DOS utilites (see their web-site) which supposedly
> should be able to force the 905 NIC to use a certain connection speed.
> However, I haven't been able to make these DOS work as described :-(
> 
> The 905b NIC may be better. But after my 905 experiences, I have lost all
> confidence with 3com. I will never buy 3com NICs again.

Donald Becker					  becker@cesdis.gsfc.nasa.gov
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html