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

From: Chunfeng Yun
Date: Thu Apr 08 2021 - 05:35:34 EST


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;
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