On Tue, 1 Mar 2005, Linas Vepstas wrote: > > > > - Additionally adds special token - abstract "iocookie" structure > > > to control/identifies/manage I/Os, by passing it to OS. > > > Actual type of "iocookie" could be arch-specific. Device drivers > > > could use the iocookie structure without knowing its detail. > > > > Fine. > > Do we really need a cookie? I think you do. That pair might have to disable interrupts (if there are any issues about concurrent accesses through a shared error bus). In that case, the cooke might be the old "flags" value. > > But many drivers don't need to save/restore interrupts around IO accesses. > > I think defaulting these to disable and restore interrupts is a very bad idea. > > They should probably be no-ops in the generic case. > > Yes, they should be no-ops. save/resotre interrupts would be a bad idea. But they may be part of that the architecture wants to do (imagine a spinlock protecting a sub-segment of a bus - you need to disable interrupts to avoid deadlocks). Linus - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.htmlReceived on Tue Mar 1 14:36:46 2005
This archive was generated by hypermail 2.1.8 : 2005-08-02 09:20:36 EST