Re: [PATCH RFC] gpio: pca953x: Configure wake-up path when wake-up is enabled

[Ulf Hansson]

[...]

> > > However, while this approach is known to work fine on other boards, with
> > > other GPIO and interrupt controllers (gpio-rcar, irq-renesas-irqc,
> > > irq-renesas-intc-irqpin), it wouldn't work on Ebisu-4D, due to different
> > > device suspend ordering.
> > >
> > > The proper ordering is:
> > >   1. When gpio-keys is suspended, its suspend handler calls
> > >      enable_irq_wake(), invoking pca953x_irq_set_wake(), and causing
> > >      pca953x_chip.wakeup_path to be incremented,
> > >   2. When gpio-pca953x is suspended, it checks pca953x_chip.wakeup_path,
> > >      and marks the device to be part of the wake-up path.
> >
> > Right.
> >
> > >
> > > However, gpio-keys is suspended _after_ gpio-pca953x, breaking the
> > > scheme :-(
> >
> > Would it make sense to fixup the ordering issue via creating a
> > parent/child relationship or setting up a device link?
>
> Could that be due to gpio_keys not having rudimentary Runtime PM support?

You are saying that the parent/child relation ship is already there?

In such case, it shouldn't matter whether runtime PM is deployed or
not, the PM core should propagate the wakeup_path flag from children
to parents in __device_suspend() and in device_suspend_late(). If that
doesn't happen there is bug in the PM core.

Kind regards
Uffe