Am Freitag, 6. Juli 2007 schrieb Benjamin Herrenschmidt: > On Fri, 2007-07-06 at 09:13 +0200, Rafael J. Wysocki wrote: > > > > The only reason (I know of) why we don't handle uninterruptible tasks in the > > freezer is that we're afraid of the suspend process deadlocking with an > > uninterruptible task holding a lock, but AFAICS the probability of such an > > event is extremely small. > > What would deadlock specifically ? One of the drivers trying to acquire > that lock ? It would be a driver bug then. Your driver's write method looks like: mutex_lock(); poke_some_hardware(); wait_event_uninterruptible(); //for result res = evaluate_result(); mutex_unlock(); return res; If you put a task into the refrigerator at wait_event_interruptible() you will deadlock if you need this lock for the driver to go to suspend. The suspend method then must not take the lock _and_ it must be aware that there may be an ongoing operation. Regards Oliver _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
