On 12 November 2015 at 02:06, Rafael J. Wysocki <r...@rjwysocki.net> wrote: > On Wednesday, November 11, 2015 12:03:52 PM Ulf Hansson wrote: >> On 11 November 2015 at 00:57, Rafael J. Wysocki <r...@rjwysocki.net> wrote: >> > On Tuesday, November 10, 2015 02:00:38 PM Ulf Hansson wrote: >> >> +Rafael, Alan >> >> >> >> On 10 November 2015 at 11:10, Geert Uytterhoeven <ge...@linux-m68k.org> >> >> wrote: >> >> > Hi Ulf, >> >> > >> > >> > [cut] >> > >> >> >> >> >> >> The problem is that the runtime PM status of the device isn't >> >> >> correctly updated at ->remove(). The effect is that the the >> >> >> pm_runtime_get_sync() in ->probe() at re-bind will *not* trigger the >> >> >> ->runtime_resume() callbacks to be invoked, as the runtime PM core >> >> >> believes the device is already runtime resumed. >> >> > >> >> > So that's where it should be fixed? >> >> >> >> That would be a more generic approach, although I am not sure how the >> >> driver/PM core should be able to take the correct decision in this >> >> phase. Devices may be runtime PM managed also without a driver bound. >> >> >> >> Perhaps when __device_release_driver() finds a bounded driver for the >> >> device, it could after all actions been performed to unbind the >> >> driver, check if runtime PM is enabled. If it isn't, it could set the >> >> runtime PM status to suspended!? >> >> >> >> I have no idea if that would introduce other issues as it would kind >> >> of force the runtime PM status of the device to suspend, without >> >> actually knowing if it's the correct thing to do. >> > >> > IMO, that needs to depend on the bus type. If the bus type has a way >> > to manage PM for devices without drivers, it should be allowed to do so. >> >> By following my suggestion above, we would allow the bus/driver's >> ->remove() to manage whether runtime PM should be enabled/disabled for >> the device, before __device_release_driver() checks that. >> Don't you think that the driver core could rely on that information? >> >> I realize that it would be a kind of policy decision for runtime PM, >> but it's quite similar as when register/unregister devices when we set >> the runtime PM status to suspended. > > OK > > If we did that, all devices that had just been unbound from their drivers > and had runtime PM disabled after that would be set to "suspended" by the > core, right?
Yes, that's the idea. I will send a patch we can test. > > If that helps, I don't really have objections. > Thanks! Kind regards Uffe -- 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/
