[tulip-bug] Recurring Lite-on PNIC loss of traffic after unplug/replug from switch

[Simen Timian Thoresen]

John,
Thank you for your response.

I've taken the liberty of cc'ing to tulip-bug@scyld.com

> Simen,
> 
> I see from your message to the tulip-bug list that you are using the
> Kingston KNE110TX.  I also note that you state "100baseTx-FD,
> performance is great".
> 
> My own experience with tulip cards (Kingston KNE100TX; KNE110TX;
> KNE111TX) is that when 100baseTx-FD is autonegotiated then performace
> may be great with smaller block sizes but with 4093 bytes and above can
> cause a slowdown by a factor of 100 or so and a big increase in
> transmission errors!  See the thread on the tulip list with the title
> "v0.92 and NetPIPE 2.4" for more details.

Hmmm. I will check that out.
 
> We intend to use the KNE110TX in some of our products and the way I plan
> to fix this problem is to use mii-diag to restrict the advertised media
> types to half-duplex only.  I have not (yet?) seen an autonegotiation
> problem when this has been done.

But do you then get full-duplex? In a two-way traffic situation, using full 
duplex can be quite useful :-)

It seems that the 100baseTX media type is used after a cable replug/switch 
repower incident, but I need to ifconfig the interface again to 'unlock' the tx 
queue (I've only been able to analyse this once, as I've only recently tried the 
tulip-diag and mii-diag utils as mentioned.

> Out of interest, have you found a specification for the Lite-On 82c168
> PNIC?  I've looked on the Lite-On web and ftp sites but not found one.
No, I have not.

Btw, it seems that Kingston actually is dropping the KNE110TX, in favor of 
the KNE111TX. I got my first card like that today, and swapped it into a 
machine for a brief 'does the driver even detect the card'-type test.
The stock-2.2.18 kernel tulip driver (v0.91g-ppc, I guess) supports the card, 
and identifies it as a PNIC-II, but without saying anything about a tranciever. I 
managed to find some info on the PNIC-II, but not much useful besides 
Becker noting that the two were designed by different teams and are quite 
different.

At this point I wouldn't choose hte KNE111TX based on the merits of the 
KNE110TX.

I'll see if I can report anything else when we start using the 111s here.

Yours,
-Simen
--
Simen Thoresen, Beowulf-cleaner and random artist.

Er det ikke rart?
The gnu RART-project on http://valinor.dolphinics.no:1080/~simentt/rart