Wednesday, January 13, 2010

A "modern" elxl driver

I undertook this past weekend an effort to "port" the NetBSD "ex" driver to GLDv3, as an open source replacement for "elxl".

It took a bit over 2 days.

The new sources are on line in a webrev format. I'd really appreciate feedback. I'm hoping to integrate these changes soon (and I could use help with testing!)

This new version, apart from being Open Source, also has with it:

1. Full support for VLANs (including full-MTU frames)
2. Full support for link notification on twisted pair (and hopefully also fiber)
3. Full integration with Brussels for MII and media selection.
4. Full support for Suspend/Resume (S3)
5. Full support for Quiesce (fast reboot)
6. Support for additional devices

It can also be extended fairly easily to support Cardbus and MiniPCI variants, and hardware checksum offload. (The checksum offload part is basically written and #ifdef'd out until I find a newer card to test with personally.)

What is missing is "automatic" media selection based on active probing. The old Solaris driver would "autoselect" which port (BNC, AUI, twisted pair) to use based on some active probes to look for link. These were rather complex, and not something I could take from the closed driver. These days everyone just uses twisted pair anyway, right? (The fiber and TX4 cards don't offer any choices, so there is no probing needed for them.)

If you have such a COMBO card, you can force the media using a new "driver private" property called "_media", which you can set to various values. See the driver sources in the webrev for more information.

I've done enough work on this driver that there is probably as much of my own code in it (at least) as was in the original NetBSD code. Nonetheless, I'd like to than the NetBSD Foundation for making these sources available.

I'll be posting binaries soon, stay tune. (Sun internal users can grab the binaries from /net/temecula.sfbay/data/work/gdamore/yge/yge/usr/src/uts/intel/elxl/ -- at least for now. That path is likely to work until I get the code integrated.)

1 comment:

Alexander said...

thanks for the great work and continuing effort to port audio and net drivers!