On Fri, Jun 10, 2016 at 12:27:16PM -0500, Andy Gross wrote: > On Fri, Jun 10, 2016 at 06:06:56PM +0100, Lorenzo Pieralisi wrote: > > On Fri, Jun 10, 2016 at 11:52:48AM -0500, Andy Gross wrote: > > > > [...] > > > > > > (1) enter_freeze() hooks are not strictly necessary to enable > > > > suspend-to-idle (they are if we want the tick to be frozen > > > > on suspend-to-idle, which is different) > > > > > > I'd think that you'd want the tick frozen. Even if you are going to > > > just call the deepest freezable idle state in your freeze_function, > > > you don't want to keep getting woken up as this costs some power usage > > > > As I said, that's a separate issue from these bindings. > > I kind of see that coupled with the determination that a idle state > supports freeze. Or are you wanting to have something else that > decides whether or not to configure the enter_freeze? All PSCI based idle state support freeze, as long as most of the other idle routines for ARM 32-bit, I do not even think we should bother with defining DT bindings for it. [...] > > For 64-bit you do not have to have add any facility. > > > > 1) we should change core code to make PM_SUSPEND_FREEZE independent > > of suspend_set_ops() > > So then, if cpuidle is active and you have idle states supporting > freeze, then you can always implicitly freeze the system. This would > infer then that the system will always indicate it can do freeze. I > am good with that. > > For now, we can get away with just implementing the changes you are > suggesting. Cracking. > > 2) we should define which idle states are freezable (99% of them are > > minus coupled idle states), through generic bindings > > This would be in the form of a DT property? And given this property > then we'd just assign a enter_freeze() function that calls the enter() > for that state. Or would we have something else that we need to key > off of to decide to configure the enter_freeze? See above, I will give it more thought. I take an action to change core code as per discussion above. Thanks for raising the point. Lorenzo -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
