On Mon, 28 Sep 2015, Rafael J. Wysocki wrote: > Hi Alan, > > On Mon, Sep 28, 2015 at 4:29 PM, Alan Stern <st...@rowland.harvard.edu> wrote: > > On Mon, 28 Sep 2015, Rafael J. Wysocki wrote: > > > >> > This suggests we forget about power/wakeup == "off" and introduce an > >> > "inhibit" attribute instead. > >> > >> If we do that, can it still be regarded as a PM attribute? > > > > Why not? Consider this: Is there any reason to support inhibit when > > CONFIG_PM is disabled? I can't come up with any. > > Well, the "I don't want any input from you now, because the phone is > going into a pocket" case?
But who would make a phone without CONFIG_PM? If you're sufficiently unconcerned about power usage that you turn off CONFIG_PM, then you probably don't care about getting excess input events either. > It isn't stticlty dependent on PM. No, not strictly. But it is closely enough related that people shouldn't mind if it becomes part of the PM code. > >> > Well, I suppose there might be a driver that supports inhibit but > >> > doesn't support runtime PM, unlikely as that seems. Or the driver > >> > might support both but the user might leave power/control == "on" while > >> > inhibiting the device. > >> > >> That sounds like a general rather than PM-related mechanism then. > > > > I don't follow your reasoning. > > Support for "inhibit" and lack of runtime PM support means that the > feature has nothing to do with PM any more AFAICS. My example above referred to support in a single driver, not support in the system as a whole. By the same reasoning, since some drivers support system sleep but not runtime PM, system sleep must have nothing to do with PM. :-) > That's why I think it may be regarded by more than just PM. It should > make runtime PM behave in a specific way if supported, but then it > should work withot it too, shouldn't it? If you want inhibit to be part of the device core rather than the PM core, that's okay with me. > My opinion is that "inhibit" should affect PM, but should not require > PM to function (there's no technical reason for that). All right. Then a design should be straightforward. 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/
