PM Sleep: Do not extend wakeup paths to devices with ignore_children set
Rafael J. Wysocki [Thu, 17 Nov 2011 20:39:33 +0000 (21:39 +0100)]
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>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base/power/main.c
include/linux/device.h
include/linux/pm.h
include/linux/pm_runtime.h

index 7fa0984..c3d2dfc 100644 (file)
@@ -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;
        }
 
index ffbcf95..52b3a41 100644 (file)
@@ -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);
index f15acb6..5c4c8b1 100644 (file)
@@ -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;
index d8d9036..d3085e7 100644 (file)
@@ -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; }