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. It may happen if the trigger level only keeps a very short time, and the interrupt controller can't process it timely, but I don't think it follow the level trigger mechanism, the HW should latch it until the ISR is called. right? > > > enable wake irq after calling runtime_suspend, e.g. at (3) or (4), > > will works. > > > > This patch seems no side effect on edge trigger wake irq. > > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> > > --- > > drivers/base/power/runtime.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c > > index a46a7e30881b..796739a015a5 100644 > > --- a/drivers/base/power/runtime.c > > +++ b/drivers/base/power/runtime.c > > @@ -619,12 +619,12 @@ static int rpm_suspend(struct device *dev, int rpmflags) > > __update_runtime_status(dev, RPM_SUSPENDING); > > > > callback = RPM_GET_CALLBACK(dev, runtime_suspend); > > - > > - dev_pm_enable_wake_irq_check(dev, true); > > retval = rpm_callback(callback, dev); > > if (retval) > > goto fail; > > > > + dev_pm_enable_wake_irq_check(dev, true); > > + > > no_callback: > > __update_runtime_status(dev, RPM_SUSPENDED); > > pm_runtime_deactivate_timer(dev); > > @@ -659,7 +659,6 @@ static int rpm_suspend(struct device *dev, int rpmflags) > > return retval; > > > > fail: > > - dev_pm_disable_wake_irq_check(dev); > > __update_runtime_status(dev, RPM_ACTIVE); > > dev->power.deferred_resume = false; > > wake_up_all(&dev->power.wait_queue); > > -- > > 2.18.0 > >
