RE: [PATCH 1/8] usb: cdns3: add runtime PM support

[Felipe Balbi <balbi@kernel.org>]

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Hi,

Peter Chen <peter.chen@nxp.com> writes:
>> Peter Chen <peter.chen@nxp.com> writes:
>> > Introduce runtime PM and wakeup interrupt handler for cdns3, the
>> > runtime PM is default off since other cdns3 has not implemented glue
>> > layer support for runtime PM.
>> 
>> it should be left disabled by default even after every glue implements it.
>> Enabling runtime PM is a policy decision better left to userspace, IMO.
>> 
>> > When the controller is in low power mode, the lpm flag will be set.
>> > The interrupt triggered later than lpm flag is set considers as wakeup
>> > interrupt and handled at cdns_drd_irq. Once the wakeup
>> 
>> This sentence doesn't parse very well. Do you want to rephrase it?
>> 
>> > occurs, it first disables interrupt to avoid later interrupt
>> > occurrence since the controller is in low power mode at that time, and
>> > access registers may be invalid at that time. At wakeup handler, it
>> > will call pm_runtime_get to wakeup controller, and at runtime resume
>> > handler, it will enable interrupt again.
>> 
>> Then what? Are you going to, somehow, process pending interrupts? At what
>> point?
>> 
>> > The API platform_suspend is introduced for glue layer to implement
>> > platform specific PM sequence.
>> 
>> I really think that's unnecessary. Why can't we rely on parent->child
>> relationship for this?
>> 
>  
> Hi Felipe,
>
> This is the old version patch; I replied your questions at your reply for new
> version at last Friday, thanks.

yeah sorry, I'm getting caught up on my inbox from oldest to
newest. This slip through the cracks ;-)

-- 
balbi

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