Messages in this thread | | | Date | Tue, 31 Oct 2023 10:39:19 -0400 | From | Alan Stern <> | Subject | Re: [PATCH] rpm: pm: enable PM_RPM_EXCEPTION config flag |
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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 >
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