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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-12-10 01:00:45 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-01-03 00:29:55 +0100
commit75e94645fc3b1007eacb4c7863059f8e8d098cda (patch)
treedb110b2815282374f08bf5d74509c73b9158cb68 /drivers/base
parent4fa3061a6856cc72f3f984702145bb30f16ee40e (diff)
PM / core: Direct DPM_FLAG_SMART_SUSPEND optimization
Make the PM core avoid invoking the "late" and "noirq" system-wide suspend (or analogous) callbacks provided by device drivers directly for devices with DPM_FLAG_SMART_SUSPEND set that are in runtime suspend during the "late" and "noirq" phases of system-wide suspend (or analogous) transitions. That is only done for devices without any middle-layer "late" and "noirq" suspend callbacks (to avoid confusing the middle layer if there is one). The underlying observation is that runtime PM is disabled for devices during the "late" and "noirq" system-wide suspend phases, so if they remain in runtime suspend from the "late" phase forward, it doesn't make sense to invoke the "late" and "noirq" callbacks provided by the drivers for them (arguably, the device is already suspended and in the right state). Thus, if the remaining driver suspend callbacks are to be invoked directly by the core, they can be skipped. This change really makes it possible for, say, platform device drivers to re-use runtime PM suspend and resume callbacks by pointing ->suspend_late and ->resume_early, respectively (and possibly the analogous hibernation-related callback pointers too), to them without adding any extra "is the device already suspended?" type of checks to the callback routines, as long as they will be invoked directly by the core. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/power/main.c85
1 files changed, 78 insertions, 7 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 3c5fdf155c91..154f7b4db8d0 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -540,6 +540,24 @@ void dev_pm_skip_next_resume_phases(struct device *dev)
}
/**
+ * suspend_event - Return a "suspend" message for given "resume" one.
+ * @resume_msg: PM message representing a system-wide resume transition.
+ */
+static pm_message_t suspend_event(pm_message_t resume_msg)
+{
+ switch (resume_msg.event) {
+ case PM_EVENT_RESUME:
+ return PMSG_SUSPEND;
+ case PM_EVENT_THAW:
+ case PM_EVENT_RESTORE:
+ return PMSG_FREEZE;
+ case PM_EVENT_RECOVER:
+ return PMSG_HIBERNATE;
+ }
+ return PMSG_ON;
+}
+
+/**
* dev_pm_may_skip_resume - System-wide device resume optimization check.
* @dev: Target device.
*
@@ -580,6 +598,14 @@ static pm_callback_t dpm_subsys_resume_noirq_cb(struct device *dev,
return callback;
}
+static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
+ pm_message_t state,
+ const char **info_p);
+
+static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
+ pm_message_t state,
+ const char **info_p);
+
/**
* device_resume_noirq - Execute a "noirq resume" callback for given device.
* @dev: Device to handle.
@@ -607,13 +633,40 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn
dpm_wait_for_superior(dev, async);
callback = dpm_subsys_resume_noirq_cb(dev, state, &info);
+ if (callback)
+ goto Run;
- if (!callback && dev->driver && dev->driver->pm) {
+ if (dev_pm_smart_suspend_and_suspended(dev)) {
+ pm_message_t suspend_msg = suspend_event(state);
+
+ /*
+ * If "freeze" callbacks have been skipped during a transition
+ * related to hibernation, the subsequent "thaw" callbacks must
+ * be skipped too or bad things may happen. Otherwise, resume
+ * callbacks are going to be run for the device, so its runtime
+ * PM status must be changed to reflect the new state after the
+ * transition under way.
+ */
+ if (!dpm_subsys_suspend_late_cb(dev, suspend_msg, NULL) &&
+ !dpm_subsys_suspend_noirq_cb(dev, suspend_msg, NULL)) {
+ if (state.event == PM_EVENT_THAW) {
+ dev_pm_skip_next_resume_phases(dev);
+ goto Skip;
+ } else {
+ pm_runtime_set_active(dev);
+ }
+ }
+ }
+
+ if (dev->driver && dev->driver->pm) {
info = "noirq driver ";
callback = pm_noirq_op(dev->driver->pm, state);
}
+Run:
error = dpm_run_callback(callback, dev, state, info);
+
+Skip:
dev->power.is_noirq_suspended = false;
if (dev_pm_may_skip_resume(dev)) {
@@ -628,7 +681,7 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn
dev_pm_skip_next_resume_phases(dev);
}
- Out:
+Out:
complete_all(&dev->power.completion);
TRACE_RESUME(error);
return error;
@@ -1223,18 +1276,26 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a
goto Complete;
callback = dpm_subsys_suspend_noirq_cb(dev, state, &info);
+ if (callback)
+ goto Run;
- if (!callback && dev->driver && dev->driver->pm) {
+ if (dev_pm_smart_suspend_and_suspended(dev) &&
+ !dpm_subsys_suspend_late_cb(dev, state, NULL))
+ goto Skip;
+
+ if (dev->driver && dev->driver->pm) {
info = "noirq driver ";
callback = pm_noirq_op(dev->driver->pm, state);
}
+Run:
error = dpm_run_callback(callback, dev, state, info);
if (error) {
async_error = error;
goto Complete;
}
+Skip:
dev->power.is_noirq_suspended = true;
if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) {
@@ -1419,17 +1480,27 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as
goto Complete;
callback = dpm_subsys_suspend_late_cb(dev, state, &info);
+ if (callback)
+ goto Run;
- if (!callback && dev->driver && dev->driver->pm) {
+ if (dev_pm_smart_suspend_and_suspended(dev) &&
+ !dpm_subsys_suspend_noirq_cb(dev, state, NULL))
+ goto Skip;
+
+ if (dev->driver && dev->driver->pm) {
info = "late driver ";
callback = pm_late_early_op(dev->driver->pm, state);
}
+Run:
error = dpm_run_callback(callback, dev, state, info);
- if (!error)
- dev->power.is_late_suspended = true;
- else
+ if (error) {
async_error = error;
+ goto Complete;
+ }
+
+Skip:
+ dev->power.is_late_suspended = true;
Complete:
TRACE_SUSPEND(error);

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