Tulip driver in 2.0.29 up

Doug Ledford (dledford@dialnet.net)
Thu, 03 Apr 1997 17:43:05 -0600

When looking into the file Documentation/networking/net-modules.txt, there is
a note under the Tulip driver about its modularization. The note indicates
that there is a problem with memory allocation in the driver when run as a
module. Could someone who knows what this problem is suppossed to be please
let me know. I intend to get this problem fixed, and right off the bat I'm
not seeing the problem (and I am currently running it as a module, and I've
already added the code to be able to specify the base io address of the card
and limit it to finding one card based on that io address). There happens to
be a half way decent reason why I'm doing all of this. In the notes in the
tulip driver, it admits that the media detection routine is simplistic (and
easy to break :) This has caused me problems in the past on a very heavy
loaded 10Mbit/s network. The detection mechanism would spot a timeout, then
switch to 100Mbit/s mode, and then never really work again. So, a person
could use the FIX_PORT option, but that doesn't work if you have tulip cards
on both 10 and 100 Mbit/s networks in the same machine (a gateway machine).
The mods I've made so far allow you to fix the port speed, specifiy the port
speed, specify the io address, and insert individual modules per card so that
you can lock different cards at different rates. All of this was accomplished
with a few lines in the /etc/conf.modules file such as:

alias eth0 tulip0
alias eth1 tulip1
options tulip0 io=0x6600 fix_port=1 port_type=1 (1 = 100Mbit/s)
options tulip1 io=0x6700 fix_port=1 port_type=0 (0 = 10Mbit/s)

(I symlinked tulip.o to tulip0.o and tulip1.0 to get around some aliasing
conflicts)

Now, having got all that done, and currently having these modules running, I'm
trying to figure out what exactly that note in the documentation about net
modules was all about :) The only idea I came up with was that maybe someone
has had problem with repeated load/unloading of the module? Anybody know what
exactly the problem with it was?

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