On 18/12/14 01:58, Rafael J. Wysocki wrote: >>>> What's needed to solve this problem is a generalized way to have runtime >>>> > >> PM dependencies between devices. Runtime PM already automatically >>>> > >> handles parent devices as one type of dependent device (e.g. a parent >>>> > >> device needs to be runtime PM resumed before its child.) So what's >>>> > >> needed is a generic way to other PM dependencies with the runtime PM >>>> > >> core (not the genpd core.) >>> > > >>> > > Considering the example above with three devices, device D1 and D2 are >>> > > passive components in this power domain. These devices only need to >>> > > know the state changes of the power domains but would not control the >>> > > power domain themselves nor put forth constraints in the power domain >>> > > state changes. So I did not clearly understand as to how this example >>> > > could be solved by introducing changes in runtime PM core. >> > >> > Your solution only solves the problems for devices managed by genpd. >> > >> > If I understood your example correctly, what you really want to solve >> > this problem more generically is to be able to tell the runtime PM core >> > that D3 has a dependency on D1 and D2. Then, whenver the runtime PM >> > core is doing get/put operations for D3, it needs to also do them for D1 >> > and D2. Indeed, I think it would solve most of the problems if we were able to model the PM dependencies between devices which would then be handled in the PM core. I recall something like this has been proposed a while ago [1]. >> > This will accomplish the same as your proposed approach, but work for >> > any devices in any PM domains. > > Plus, it is not limited to runtime PM, really. It affects system suspend > too. [1] https://lkml.org/lkml/2009/8/26/485 -- Regards, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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