On Thu, 14 Apr 2005 13:07:16 -0700 David Brownell <[EMAIL PROTECTED]> wrote: > On Thursday 14 April 2005 12:56 pm, Pete Zaitcev wrote: > > On Thu, 14 Apr 2005 11:33:00 -0400 (EDT) Alan Stern <[EMAIL PROTECTED]> > > wrote: > > > > > Is it true then, on all architectures, that the hardware will complete the > > > outw() _before_ the CPU executes the udelay() routine, even without the > > > mb()? > > > > It should be true, but I cannot guarantee that all architectures are > > bugless. > > It will NOT be true on most architectures that implement outw() though > memory space operations ... since memory writes normally land in some > sort of write buffer.
Yes it is true. They just add flush instructions to outw like PPC does, or use special instructions like stuba at SPARC. Remember, outw does not have to map to a single instruction. It can be a hefty function. -- Pete ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
