USB locking

[Lukas Ertl]

Hello,

I've prepared a patch that adds some basic locking primitives to parts of 
the USB stack (usb.c, uhci.c, ehci.c).  Mainly, I've added some mutexes 
and applied them instead of calls to spl*, wrapped into #ifdef's to stay 
somewhat compatible with NetBSD.  I'd be happy if I could get some review.

<http://people.freebsd.org/~le/usb.diff>

thanks,
le

-- 
Lukas Ertl                           eMail: l.ertl at univie.ac.at
UNIX Systemadministrator             Tel.:  (+43 1) 4277-14073
Vienna University Computer Center    Fax.:  (+43 1) 4277-9140
University of Vienna                 http://homepage.univie.ac.at/l.ertl/