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authorRafael J. Wysocki <rjw@sisk.pl>2011-12-01 03:01:31 +0400
committerRafael J. Wysocki <rjw@sisk.pl>2011-12-02 00:46:42 +0400
commit00dc9ad18d707f36b2fb4af98fd2cf0548d2b258 (patch)
treef41672d9dae9bf15f2ee17abf3b5b6c31c966088 /include/linux/pm_qos.h
parentb930c26416c4ea6855726fd977145ccea9afbdda (diff)
downloadlinux-00dc9ad18d707f36b2fb4af98fd2cf0548d2b258.tar.xz
PM / Runtime: Use device PM QoS constraints (v2)
Make the runtime PM core use device PM QoS constraints to check if it is allowed to suspend a given device, so that an error code is returned if the device's own PM QoS constraint is negative or one of its children has already been suspended for too long. If this is not the case, the maximum estimated time the device is allowed to be suspended, computed as the minimum of the device's PM QoS constraint and the PM QoS constraints of its children (reduced by the difference between the current time and their suspend times) is stored in a new device's PM field power.max_time_suspended_ns that can be used by the device's subsystem or PM domain to decide whether or not to put the device into lower-power (and presumably higher-latency) states later (if the constraint is 0, which means "no constraint", the power.max_time_suspended_ns is set to -1). Additionally, the time of execution of the subsystem-level .runtime_suspend() callback for the device is recorded in the new power.suspend_time field for later use by the device's subsystem or PM domain along with power.max_time_suspended_ns (it also is used by the core code when the device's parent is suspended). Introduce a new helper function, pm_runtime_update_max_time_suspended(), allowing subsystems and PM domains (or device drivers) to update the power.max_time_suspended_ns field, for example after changing the power state of a suspended device. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'include/linux/pm_qos.h')
-rw-r--r--include/linux/pm_qos.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
index 83b0ea302a80..775a3236343d 100644
--- a/include/linux/pm_qos.h
+++ b/include/linux/pm_qos.h
@@ -78,6 +78,7 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_request_active(struct pm_qos_request *req);
s32 pm_qos_read_value(struct pm_qos_constraints *c);
+s32 __dev_pm_qos_read_value(struct device *dev);
s32 dev_pm_qos_read_value(struct device *dev);
int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
s32 value);
@@ -119,6 +120,8 @@ static inline int pm_qos_request_active(struct pm_qos_request *req)
static inline s32 pm_qos_read_value(struct pm_qos_constraints *c)
{ return 0; }
+static inline s32 __dev_pm_qos_read_value(struct device *dev)
+ { return 0; }
static inline s32 dev_pm_qos_read_value(struct device *dev)
{ return 0; }
static inline int dev_pm_qos_add_request(struct device *dev,