[realtek] Complete kernel crash with Ovislink Fast Ethernet Cardbus 10/100

[Joao Dias]

Dear sirs, 

I am just reporting a problem wich I can no longer debug because I have
not the appropriate skills nor the time to do it(actually
it consumed me quite time to trace the problem to this point)

The problem happens when using the PCMCIA Ovislink card at 100Mb/s with
linux (I just bought it new),
and it does not allow the use of remote X sessions in my notebook, wich
is an old model but that is
actually referred by Ovislink as one of the models they tested the card
in.

This can be a problem with the driver 8139too, the PCMCIA subsystem or
the kernel itself.

How I reach a complete crash of my notebook:

Connect two linux hosts with a cross-cable (in my case both with
Libranet 2.8.1, but saw it happens with others)
One of my hosts is a notebook Toshiba Portege 300CT, did not test
others.

Both kernel are 2.4.21 (doesn't matter they are Libranet original or
recompiled)

After configuring network and firewall hosts.allow, and adding xhost+
neptuno in Toshiba...

from the Toshiba I start a remote X session in the other PC

ssh -Y neptuno
...

start a remote image browser and browse a few 1M photos (say 1-30 should
be enough)

gthumb --display 192.168.2.2:0.0

after some random network traffic the Toshiba crashes completely(!)

This only happens in 100Mb/s link if it is a real one, I mean, if I
connect at 100Mb/s via a hub and the application
server is using a 10Mb/s network card also connected to the hub this
does not happen (exchanged more than 350MB in remote X
configuration this way and worked fine).

My PCMCIA card has this serial BPCM32D-5030255

Doesn't matter what the other network card is (nor the other kernel
version, crashed also with Fedora Core3)
and it is not from the network cable, tested two diferent cross cables.

I will just downgrade the application server card to a 10MB one as that
will solve the case for me, but 
if someone knows the solution, I will apreciate that he/she lets me know
how to do it as 100MB works real fast
and I wanted to use it. This can be relevant for other people than me,
so maybe Ovislink or the 8139too developers
 will be interested in checking what is happening here.

I can't give any log information cause I get none. I t simply blocks
completely the Toshiba.
Its not from the X11 server because I tested switching the role
situation with diferent X server versions 
and it is always Toshiba that crashes. Seems related to achieving a
certain amount of fast network traffic.

(I am not subscribed to any related mailing list so please send replies
directly to my address please)

I also thank if someone can post this in some forum of kernel 2.4
mantainers or bug report this, as couldn't find how to do it
and don't want to subscribe high traffic mailing lists

(realtek people please do not forward directly this as you are all
receiving invdividual copies and you will all together overload intended
recipients if it is the same)


Thank you
Joao Dias