Yet another Ethernet driver...this time, it's the Olicom 2335, the only 100 MBit Ethernet board for the Microchannel that was ever built. It is based on the National DP83800 NIC.
For a long time, there was barely hope that such a driver would ever become reality, mainly due to Olicom's absolute unwillingness to provide programming documentation about the card. A fairly dumb position, since the card is just a 83800 with an MCA bus adaption logic, and the datasheet is available from National Semiconductor.
You may download the sources here. The driver was developed with kernel version 2.2.17 and tested on a P90-based 9595 server. The provided version also runs with a 2.4.1 kernel, but you have to patch it in yourself... It will possibly also work with a 2.0 kernel prepatched with the MCA patches patches available on www.dgmicro.com. Of course, the 2.2.17 patch provided won't work with this kernel either since the Makefile structure is different, but if you're still using kernel 2.0, you're probably anyway a die-hard ;-). I am planning to test it agains the latest 2.4 kernel and submit it for inclusion as soon as I receive positive feedback from other users.
Configurations with more than one card should theoretically be possible, however I cannot confirm this due to lack of hardware.
The performance is as good as one could expect it to be from such a 'hampered' design: The chip's ISA-style bus interface limits the effective transfer rate to about 3 MBytes/second in 100M mode, and the small Tx buffer results in suboptimal 10MBit Tx performance either. You have to take what you can get...
The driver is GPL, so you are free to use and improve it, but like always, it comes without any warranty: If you smash something with it, you're the proud owner of all remaining chunks ;-)
Apart from the driver sources themselves, you will find a patch file to modify some other files in the Linux kernel tree. This way, the driver will show up as a configuration option just like all other network drivers. The patches are relative to a 2.2.17 source tree, but should also work with other 2.2 series kernels without too much hassle.
A big thank you to 'Don' Peter Wendt for providing me an Olicom 2335 to write this driver - it wouldn't have been possible without him...
© Alfred Arnold,