[Soekris] Net5501: USB devices & attach/detach events

[Bernd Walter]

On Wed, May 28, 2008 at 04:08:23PM -0400, Guy F. Boyd wrote:
> 
> > From: Tuc at T-B-O-H.NET [mailto:ml at t-b-o-h.net]
> > Sent: Wednesday, May 28, 2008 3:16 PM
> > Subject: Re: [Soekris] Net5501: USB devices & attach/detach events
> > Guy,
> > 	It seems there is a current "USB not working right" thread on
> > freebsd-questions which I've also chimed in on. Maybe if
> > enough people
> > state there is a problem, it might be paid attention to.
> >
> 
> Thanks, but being as it all Does The Right Thing here if the devices aren't
> attached via an intervening USB hub, I'm not so sure (yet) that it's a software
> issue.

Things are different for USB2 with hubs.
Let me explain a bit background first.
You have a high speed (480mbps) (EHCI in this case) controller and a
controller for low (1.5mps) and full speed (12mbps) (not sure either
OHCI or UHCI for 5501).
Both controllers share the same physical connectors.
High speed is new since USB2.0, but USB2.0 doesn't mean it has to
be high speed.
If you connect a low or full speed device to a host port it gets handled
by the full speed controller.
If you connect a high speed device to a host port it gets handled by the
high speed controller, or - if you don't have driver support enabled - by
the low/full-speed controller running at full speed only.
If you connect a high speed hub it gets handled by the high speed
controller, or it falls back to full/low-speed mode.
Now if you connect a low or full speed device to a high speed hub
running in high speed mode it is seen on the host at the high speed
controller, with the hub doing speed translation, since the controller
itself can't do anything else than high speed.
I'm not sure, but it might be possible that FreeBSD-6 has no support for
hubs doing speed translation yet.
In that case the device just isn't there.
You need to use a full/low speed hub or disable ehci controller support
in kernel or upgrade to FreeBSD-7.

-- 
B.Walter <bernd at bwct.de> http://www.bwct.de
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.