On Tue, Oct 31, 2023 at 05:38:55PM +0800, Guan-Yu Lin wrote: > Introducing PM_RPM_EXCEPTION config flag, which may alter the priority > between system power management and runtime power management. In > suspend-to-idle flow, PM core will suspend all devices to avoid device Your patch affects all forms of system suspend, not just suspend-to-idle. What do you actually mean here? > interact with the system. However, chances are devices might be used by > other systems rather than a single system. In this case, PM core shouldn't > suspend the devices. One may use PM_RPM_EXCEPTION config flag to mark > such exception, and determine the power state of a device with runtime > power management rather than system power management. This sort of arrangement -- a device shared between two different systems -- could happen with any sort of device. Why does your patch affect only USB devices? > diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig > index 4b31629c5be4..beba7a0f3947 100644 > --- a/kernel/power/Kconfig > +++ b/kernel/power/Kconfig > @@ -193,6 +193,14 @@ config PM > responsible for the actual handling of device suspend requests and > wake-up events. > > +config PM_RPM_EXCEPTION > + bool "Prioritize Runtime Power Management more than Power Management" Runtime Power Management is a form of Power Management, so what you wrote doesn't make sense. What you really meant is: Prioritize Runtime Power Management more than System Power Management. > + default n > + help > + Provides a way to prioritize Runtime Power Management more than Power > + Management. This way system can suspnd with maintaining specific s/suspnd/suspend/ s/with/while/ > + components in operation. Your patch does not allow _specific_ components to be kept in operation. _All_ in-use components that support prioritized PM (with this patch, all USB components) will remain powered during system suspend, even if the user wants only _some_ of them to be kept powered. Alan Stern > + > config PM_DEBUG > bool "Power Management Debug Support" > depends on PM > -- > 2.42.0.820.g83a721a137-goog >
