On Sat, 31 Oct 2015, Rafael J. Wysocki wrote: > Runtime PM uses a freezable workqueue, allocated in pm_start_workqueue(). > > That's because we don't want async runtime PM to happen during system > suspend/resume and for good reasons, so if you want to remove the freezing > mechanism, you need to stop that workqueue at the beginning of dpm_prepare > and start it again at the end of dpm_complete().
The same sort of thing is true for the USB hub driver's workqueue. Since it registers new devices (as a result of hotplugs), it must stop running at the beginning of the dpm_prepare stage. Of course, that's also a workqueue and not a kthread. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
