On Fri, Oct 12, 2012 at 08:59:36AM +1030, Rusty Russell wrote: > >> For writes, the standard seems to be a commit latch. We could abuse the > >> generation count for this: the driver writes to it to commit config > >> changes. > > > > I think this will work. There are a couple of things that bother me: > > > > This assumes read accesses have no side effects, and these are sometimes handy. > > Also the semantics for write aren't very clear to me. > > I guess device must buffer data until generation count write? > > This assumes the device has a buffer to store writes, > > and it must track each byte written. I kind of dislike this > > tracking of accessed bytes. Also, device would need to resolve conflicts > > if any in some device specific way. > > It should be trivial to implement: you keep a scratch copy of the config > space, and copy it to the master copy when they hit the latch. > > Implementation of this will show whether I've missed anything here, I > think. What I refer to: what happens if driver does: - write offset 1 - write offset 3 - hit commit latch ? -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
