Hi Alan!
Thanks for your reply!!

> > Is there any (good) way to trigger re-enumeration of the USB bus from
> > software?
>
> It's not clear that this is a good idea.  It would mean losing all the
> settings for devices you had already enumerated.

That's OK since there aren't any other. (It's an embedded design).

>
> >  The situation is that I am working on a custom design where
> > two boards are housed in the same case and connected via USB. One
> > board runs Linux and implements the host controller. The other board
> > runs a different OS. When power is supplied, the two boards boot
> > independently and the Linux one is faster (;-). Because of some
> > shortcomings, the second board cannot reset the USB bus it's on and is
> > therefore never detected.
>
> That shouldn't matter.  USB peripherals don't have to reset anything, they
> only have to connect to the bus.  The host is supposed to take care of
> everything else.  Maybe your problem is really that the peripheral
> connects to the bus before it's ready to be enumerated.

And that's exactly it... thanks for putting it this way... I wasn't
really sure how to describe it. The USB connection is hardwired and
the host software is coming up before the software that drives the USB
part of the peripheral.

>
> >  So I am looking for a way to periodically
> > re-enumerate the USB bus under software control from the Linux side.
>
> One way to do it, although a pretty drastic way, is to rmmod the host
> controller driver module and then modprobe it.

I thought about that. However, the kernel I am using 2.4.22 (uclinux)
does not like that. So I am looking for some function to call or ioctl
to send that would trigger re-enumeration.

Thanks again for your help,
Patrick


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