[Fwd: Problem with USB Webcam under OHCI?]

Andrew Boothman andrew at cream.org
Tue Sep 10 16:30:55 BST 2002

Paul Civati wrote:

>>ohci_device_isoc_start: not implemented
>>on the console. Worse, the vid process hangs and if I try to kill it 
>>(but not before then) the whole machine hangs!
>>I searched the archives and googled but I couldn't see anything 
>>relevent. I do note that the controller that the cam worked on was UHCI, 
>>but failed on an OHCI one. I've no idea if that's relevent though.
>I think (guess!) this is pretty key to the problem, bearing in mind
>the "not implemented" above.
>I suggest the FreeBSD USB page <URLhttp://www.etla.net/~n_hibma/usb/>
>might be useful, it references a (english speaking) bsd-usb mailing
>list near the bottom.
Many thanks Paul, I didn't know that web site existed!

After searching through the bsd-usb list archives, I've found someone 
else reporting exactly the same problem. It appears that isochronous 
transfers on OHCI controllers are only supported under -current, not 
-stable. Problem is, I can't really run -current on this machine as it 
is supposed to be a 'production' server. I may do temporarily however to 
make sure that -current's USB stack does solve the problem.

Thanks again.


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