On Mon, 13 Aug 2012, Rafael J. Wysocki wrote: > > I guess the best we can say is that if you call pm_runtime_barrier() > > after updating the dev_pm_ops method pointers then after the barrier > > returns, the old method pointers will not be invoked and the old method > > routines will not be running. So we need an equivalent guarantee with > > regard to the pm_runtime_work pointer. (Yes, we could use a better > > name for that pointer.) > > > > Which means the code in the patch isn't quite right, because it saves > > the pm_runtime_work pointer before calling rpm_resume(). Maybe we > > should avoid looking at the pointer until rpm_resume() returns. > > Yes, we can do that. > > Alternatively, we can set power.work_in_progress before calling > rpm_resume(dev, 0) (i.e. regard the resume as a part of the work) to make > the barrier wait for all of it to complete.
Yep, that would work. In fact, I did it that way in the proposed code posted earlier in this thread. (But that was just on general principles, not because I had this particular race in mind.) Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
