[tulip-bug] FreeBSD Problems with dc(4) ADMtek AN985 chip

Martin Blapp mb@imp.ch
Thu Sep 5 12:07:01 2002

Hi everybody,

(I also wrote to the linux tulip list, maybe someone has encountered
the bug in linux too as I do ?)

My notebook has a Accton EN2242 network chip, which
is integrated into a VIA PN133 chipset.

I encounter serious connection problems as desribed in the
manpage. I have to replug the cable over and over again till
it works. And then the connection stays about some seconds and then
it get wedged again. Unusable ...

>From a cold boot into Linux, is see the same symptoms as FreeBSD.
Linux kernel 2.4.9-13 ... The windows driver seems to work :-( .

>From the FreeBSD dc manpage.

     The ADMtek AL981 chip (and possibly the AN985 as well) has been observed
     to sometimes wedge on transmit: this appears to happen when the driver
     queues a sequence of frames which cause it to wrap from the end of the
     transmit descriptor ring back to the beginning.  The dc driver attempts
     to avoid this condition by not queuing any frames past the end of the
     transmit ring during a single invocation of the dc_start() routine.  This
     workaround has a negligible impact on transmit performance.

But this workaround seems not to work for me. For some reason, replugging
the cable works for me, ifconfig (down/up) does not.

Whe link always stays up, it is just the reciever queue with is

Have other people the same problem with the dc driver ? If you own
such a card here:

Linksys EtherFast LNE100TX
Accton EN2242

Please tell me your experiences.


Martin Blapp, <mb@imp.ch> <mbr@FreeBSD.org>
ImproWare AG, UNIXSP & ISP, Zurlindenstrasse 29, 4133 Pratteln, CH
Phone: +41 061 826 93 00: +41 61 826 93 01
PGP: <finger -l mbr@freebsd.org>
PGP Fingerprint: B434 53FC C87C FE7B 0A18 B84C 8686 EF22 D300 551E