Hi, (I know I suggested switching to the other thread but I just want to explain my reasoning here!) On Wed, Aug 31, 2016 at 04:19:41PM +0200, Ulf Hansson wrote: > On 31 August 2016 at 12:16, Brendan Jackman <brendan.jackman@xxxxxxx> wrote: [...] > > There was some previous discussion of whether device idle state bindings are > > necessary. It was proposed that rather than adding a whole new binding, we could > > just use the power domain idle state binding from [2]. We suggested that any > > device that has an idle state is, by definition, in a power domain of its own: > > rather than add a device-idle-states property to that device, we just put it in > > a power domain with a domain-idle-states property. > > Yes, we can do that software wise, but is that really a proper > description of the HW!? > It's probably not what SoC docs would explicitly list under "power domains" but I think "set of components that are bound by a common power state" is a reasonable definition for a power domain. I think (?) your objection is that a device could have idle states that it controls by itself and does not switch "off", for example in the case of a device that has an idle state where it gates its clock but does not cut voltage, or WFI in an ARM CPU. My thinking is: just because the transitions into those power states isn't triggered by a separate power controller, I don't think that means no "power domain" exists. Perhaps that's a glitch in my vocabulary. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
