Re: [PATCH 1/6] PM: runtime: enable wake irq after runtime_suspend hook called

From: Tony Lindgren
Date: Fri Apr 09 2021 - 01:39:29 EST


* Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> [210409 01:54]:
> On Thu, 2021-04-08 at 19:41 +0200, Rafael J. Wysocki wrote:
> > On Thu, Apr 8, 2021 at 11:35 AM Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> wrote:
> > >
> > > When the dedicated wake irq is level trigger, enable it before
> > > calling runtime_suspend, will trigger an interrupt.
> > >
> > > e.g.
> > > for a low level trigger type, it's low level at running time (0),
> > > and becomes high level when enters suspend (runtime_suspend (1) is
> > > called), a wakeup signal at (2) make it become low level, wake irq
> > > will be triggered.
> > >
> > > ------------------
> > > | ^ ^|
> > > ---------------- | | --------------
> > > |<---(0)--->|<--(1)--| (3) (2) (4)
> > >
> > > if we enable the wake irq before calling runtime_suspend during (0),
> > > an interrupt will arise, it causes resume immediately;
> >
> > But that's necessary to avoid missing a wakeup interrupt, isn't it?
> That's also what I worry about.

Yeah sounds like this patch will lead into missed wakeirqs.

Regards,

Tony