OpenUSB for FreeBSD?

[Hans Petter Selasky]

Hi,

On Thursday 15 November 2007, Xiaofan Chen wrote:
> On 11/12/07, Henrik Brix Andersen <brix at freebsd.org> wrote:
> > > Is it possible for some people here to implement a backend
> > > (based on ugen?) for FreeBSD?
> >
> > Interesting - definitely something I will take a look at. Thank you
> > for the pointer.
> >
> > > Or maybe at least improve the current libusb-0.1.x implemenation
> > > for FreeBSD.
> >
> > Yeah, I was looking at backporting some of the features from libusb
> > CVS HEAD to libusb-0.1 on FreeBSD a while back and improving FreeBSD
> > compatability as well for an application, I work on - but we ended up
> > making FreeBSD specific work-arounds in the application instead.
>
> Could you be a bit more specific? I know there are some missing calls
> in FreeBSD. And I have problems with libusb interrupt write with the
> default kernel (hangs). It is documented here.
> http://lists.freebsd.org/pipermail/freebsd-usb/2007-November/004128.html
> But I am not so sure if it is a libusb problem or the kernel USB driver
> problem.

The problem about clear stall on the interrupt endpoint is a pure device 
problem. Your USB device must re-queue any lost interrupt packets after clear 
stall!

>
> The HPS stack seems to be better in this aspect and I got
> some libusb application ported from Linux/Windows to
> FreeBSD thanks to the help from Hans.
>
> > The current stable version of libusb certainly makes a lot to wish for
> > on FreeBSD.
>

I haven't got time yet to look at the latest version of libusb. I have some 
plans to make a replacement for /dev/ugen, that can interact on USB 
interfaces that already have drivers on them. Currently I'm very busy with 
other USB stuff.

--HPS