ASIX USB-to-Ethernet drivers

[Brett Glass]

Everyone:

Just tried to plug an ASIX-based USB-to-Ethernet interface into a 
system running FreeBSD 8.0-RELEASE, and discovered that it wasn't 
recognized. It turns out that ASIX has come out with a new version 
of one of its chips: the AX88772A. It has a smaller package with 
fewer pins, slightly less buffer memory, and a serial interface so 
that it can also support power line networking (see 
http://www.asix.com.tw/products.php?op=ProductList&PLine=71&PSeries=100). 
The AX88772 is being phased out by most interface manufacturers 
because the "A" chip is smaller and cheaper and takes up less board 
space. I am sure that I will not be the only person who is 
frustrated when plugging in an interface that looks the same as the 
older ones and finding that it doesn't work!

I've discovered that the existing axe(4) driver for FreeBSD seems 
to work on the AX88772A without any changes if it is told to treat 
the chip like an AX88772. (It may not be optimal, because the ASIX 
Linux driver code does differentiate between the two. And the 
command "systat -vmstat 1" does show a lot of IRQs -- about one per 
millisecond. Also, the link light on the interface does not work, 
though this is a minor nit that I can live with. But the interface 
does at least run.)

For the moment, I've patched /sys/dev/usb/usbdevs and 
/sys/dev/usb/net/axe to treat the AX88772A as if it were an AX88772 
(patch submitted as PR 140923) so that I can get my systems 
working. But it would probably be a good idea to do more thorough testing....

--Brett Glass