PM Sleep: Do not extend wakeup paths to devices with ignore_children set

Commit 4ca46ff3e0d8c234cb40ebb6457653b59584426c (PM / Sleep: Mark
devices involved in wakeup signaling during suspend) introduced
the power.wakeup_path field in struct dev_pm_info to mark devices
whose children are enabled to wake up the system from sleep states,
so that power domains containing the parents that provide their
children with wakeup power and/or relay their wakeup signals are not
turned off.  Unfortunately, that introduced a PM regression on SH7372
whose power consumption in the system "memory sleep" state increased
as a result of it, because it prevented the power domain containing
the I2C controller from being turned off when some children of that
controller were enabled to wake up the system, although the
controller was not necessary for them to signal wakeup.

To fix this issue use the observation that devices whose
power.ignore_children flag is set for runtime PM should be treated
analogously during system suspend.  Namely, they shouldn't be
included in wakeup paths going through their children.  Since the
SH7372 I2C controller's power.ignore_children flag is set, doing so
will restore the previous behavior of that SOC.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 7fa098464dae62921a5acf32af3537f649b604fe..c3d2dfcf438dd1735fcf401be9f8185440e9a1a9 100644 (file)
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -920,7 +920,8 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
  End:
        if (!error) {
                dev->power.is_suspended = true;
-               if (dev->power.wakeup_path && dev->parent)
+               if (dev->power.wakeup_path
+                   && dev->parent && !dev->parent->power.ignore_children)
                        dev->parent->power.wakeup_path = true;
        }
 

diff --git a/include/linux/device.h b/include/linux/device.h
index ffbcf95cd97dbb3b7e12f9be778c90f1977a9a1a..52b3a4111df916121f0353743493e78b5da38839 100644 (file)
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -682,6 +682,11 @@ static inline bool device_async_suspend_enabled(struct device *dev)
        return !!dev->power.async_suspend;
 }
 
+static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
+{
+       dev->power.ignore_children = enable;
+}
+
 static inline void device_lock(struct device *dev)
 {
        mutex_lock(&dev->mutex);

diff --git a/include/linux/pm.h b/include/linux/pm.h
index f15acb64681351b72c5b1c460bf0174ad2f33749..5c4c8b18c8b7809832d1be52808256f5a803a426 100644 (file)
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -447,6 +447,7 @@ struct dev_pm_info {
        unsigned int            async_suspend:1;
        bool                    is_prepared:1;  /* Owned by the PM core */
        bool                    is_suspended:1; /* Ditto */
+       bool                    ignore_children:1;
        spinlock_t              lock;
 #ifdef CONFIG_PM_SLEEP
        struct list_head        entry;
@@ -464,7 +465,6 @@ struct dev_pm_info {
        atomic_t                usage_count;
        atomic_t                child_count;
        unsigned int            disable_depth:3;
-       unsigned int            ignore_children:1;
        unsigned int            idle_notification:1;
        unsigned int            request_pending:1;
        unsigned int            deferred_resume:1;

diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index d8d90361964216f771ed62e5d17fb083451e2796..d3085e72a0ee9b43bbd024bf33b93939e1535d42 100644 (file)
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -52,11 +52,6 @@ static inline bool pm_children_suspended(struct device *dev)
                || !atomic_read(&dev->power.child_count);
 }
 
-static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
-{
-       dev->power.ignore_children = enable;
-}
-
 static inline void pm_runtime_get_noresume(struct device *dev)
 {
        atomic_inc(&dev->power.usage_count);
@@ -130,7 +125,6 @@ static inline void pm_runtime_allow(struct device *dev) {}
 static inline void pm_runtime_forbid(struct device *dev) {}
 
 static inline bool pm_children_suspended(struct device *dev) { return false; }
-static inline void pm_suspend_ignore_children(struct device *dev, bool en) {}
 static inline void pm_runtime_get_noresume(struct device *dev) {}
 static inline void pm_runtime_put_noidle(struct device *dev) {}
 static inline bool device_run_wake(struct device *dev) { return false; }