Hi,

please see my comment below. It might be helpful for some of you.

On Thursday 28 August 2008 23:11:51 Steven A. Falco wrote:

Alan Stern wrote:

quoted

Your original post mentioned that the 440EPx has only one USB 2.0 host
port.  Then how can you use a keyboard and memory stick at the same
time?  You'd have to plug them into a hub -- in which case only one
controller would be needed, the one driving the hub.  The patch would
be unnecessary.

I have one of these processors on a Sequoia board.  What happens is that
if you build the kernel with both EHCI and OHCI support, then plug in
a modern USB memory stick, it initially tries EHCI, the driver fails, and
the whole thing falls back to OHCI.  So you wind up running at 12 Mbps.
The only way to make high speed work is to turn off the OHCI driver, and
then you cannot support slow devices with that kernel.

There is a simple trick to get all types (full, low ang high speed) of  
devices work: use a USB hub with transaction translators. We are doing so on 
a custom design based on the 440EPx. So we only build the kernel with EHCI 
support and there was no need for this ugly hack.

So, hile you cannot plug two devices in at one time, you can plug in
different speed devices at different times, and my understanding is that
this patch will let that work seamlessly.

That's true.

Matthias