On Wed, 24 Jun 2009, Alan Stern wrote: > More comments to follow when I get time to review more of the code... Here we go. This isn't so detailed, because I wasn't able to do a detailed review. Frankly, the code is kind of a mess. The whole business about the runtime_notify and RPM_NOTIFY flags is impenetrable. My suggestion: Rename runtime_notify to notify_pending and eliminate RPM_NOTIFY. Then make sure that notify_pending is set whenever a notify work item is queued. The pm_notify_or_cancel_work routine should just be pm_notify_work. It's silly to submit a workqueue item just to cancel a delayed workqueue item! Do all the cancellations in the __pm_runtime_resume and __pm_runtime_suspend routines, where you're already in process context. If this means a work item occasionally runs at the wrong time then let it -- it will quickly find out that it has nothing to do. And while you're at it, get rid of the runtime_break flag. The logic in __pm_runtime_resume and __pm_runtime_suspend is too complicated to check. This is probably because of the interactions with RPM_NOTIFY and runtime_break. Once they are gone, the logic should be much more straightforward: test the flags, then do whatever is needed based on the status. I think once these cleanups are made, the code will be a lot more transparent. In __pm_runtime_resume, don't assume that incrementing the parent's child_count will prevent the parent from suspending; also increment the resume_count. And don't forget to decrement the parent's child_count again if the resume fails. In __pm_runtime_suspend, you should decrement the parent's child_count before releasing the child's lock. The pm_runtime_idle call should stay where it is, of course. One more thing: Don't use flush_work or its relatives -- it tends to cause deadlocks. Use cancel_work_sync instead. Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
