[Qemu-devel] RE: USB-OHCI / UHCI: Isochronous transfer not working on Linux host

[Arnon Gilboa]

Hello Thomas,

 

Since the last time I sent a patch, usb-linux.c & usb-uhci.c were completly rewritten by

Max Krasnyansky and merged by aliguori.

 

However, looking at my post below from 24 Sep 2007, you can see that usb-uhci,

which is USB 1.1 host controller emulation, was mostly tested on USB 1.1 devices.

 

I am sure that many USB 2.0 and even several 1.1 devices (especially isochronous)

will NOT work with the emulation.

 

http://lists.gnu.org/archive/html/qemu-devel/2007-09/msg00409.html

 

Regards,
Arnon

---

From: Thomas Bandelier [mailto:address@hidden
Sent: Thursday, November 27, 2008 4:06 PM
To: address@hidden
Cc: address@hidden; Arnon Gilboa
Subject: USB-OHCI / UHCI: Isochronous transfer not working on Linux host

Hi all,

Following several tests we did with qemu trunk, 
Isochronous transfer seems to be broken with the head of qemu.

We tried 
following Os (targets):
-WinXP (i386)
-Win2k (i386)
-Several linux 
kernel ( 2.6.26-1 (i386), 2.6.27 (ARM) )

On our host we are using Gentoo 
with 2.6.23 and 2.6.27 kernel.

Following USB devices were tested:
-USB 
2.0 logitech webcams
-Terratec USB2.0 Cynergy hybrid XS FM tuner.

Both 
OHCI and UHCI configurations were tested in i386 target.
Only OHCI was tested 
in ARM target.

In all these configurations, it was never possible 
to initiate isochronous USB transfer. It was possible to enumerate the devices 
but as soon as isochronous packets were used, the procedure failed. It means for 
example that no picture was retrieved from the webcams, and no audio data was 
retrieved from FM tuner.

It is important to mention that all theses 
devices perfectly work on our host.

After some search in this maling list 
archives, it seems that no work has been made on these aspects since Arnon 
Gilboa sent some patches more than one year ago. Am I wrong?

So It would 
be very useful for us to have a feedback from the community on this 
point.
Has someone met the same problems? Has someone investigated this 
aspect?
Is someone regularly using this feature?

How can we 
investigate this 
problem?

Thanks

Thomas