ASIX USB-to-Ethernet drivers

Pyun YongHyeon pyunyh at
Sun Nov 29 21:48:30 UTC 2009

On Sat, Nov 28, 2009 at 01:40:18PM -0700, Brett Glass wrote:
> 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 
> 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 

AFAIK Linux does not differentiate 88772A from 88772.
Since ASIX seems to require account to download datasheet I
couldn't check the datasheet but I guess 88772A has the same
interface for driver's view.

> command "systat -vmstat 1" does show a lot of IRQs -- about one per 
> millisecond. Also, the link light on the interface does not work, 

I think the large number of interrupts has nothing to do with
axe(4). Almost all USB ethernet controllers are poorly designed
to save cost so you can't expect reasonable performance from it and
you should have fast CPU to copy received frames in a buffer. It's
worse than rl(4) controllers.

Datasheet may have an entry to control LEDs. Linux may also have
the same problem as they don't try to program LEDs unless the PHY
is Marvell gigabit PHY.

> 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 

Maybe Hans can handle this.

> working. But it would probably be a good idea to do more thorough 
> testing....
> --Brett Glass

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