[PATCH 1/3] PM / sleep: add a helper function to inherit child ignorance

[Linus Walleij <linus.walleij@linaro.org>]

A few subsystems dealing with peripherals on slow buses with
transfer-oriented runtime PM will need to inherit the child
ignorance property of their parent hardware devices.

Especially struct i2c_adapter and struct spi_master needs
this.

This adds a helper function to deal with this and make it
clear what is going on.

Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 include/linux/device.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/linux/device.h b/include/linux/device.h
index 002c59728dbe..675c09e62239 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -961,6 +961,13 @@ static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
 	dev->power.ignore_children = enable;
 }
 
+static inline void pm_suspend_inherit_ignore_children(struct device *dev)
+{
+	if (!dev->parent)
+		return;
+	dev->power.ignore_children = dev->parent->power.ignore_children;
+}
+
 static inline void dev_pm_syscore_device(struct device *dev, bool val)
 {
 #ifdef CONFIG_PM_SLEEP
-- 
2.4.3