PM / sleep: Go direct_complete if driver has no callbacks
If a suitable prepare callback cannot be found for a given device and
its driver has no PM callbacks at all, assume that it can go direct to
complete when the system goes to sleep.
The reason for this is that there's lots of devices in a system that do
no PM at all and there's no reason for them to prevent their ancestors
to do direct_complete if they can support it.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 13a0d66..0499421 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -250,6 +250,8 @@
klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
+ device_pm_check_callbacks(dev);
+
/*
* Make sure the device is no longer in one of the deferred lists and
* kick off retrying all pending devices
@@ -766,6 +768,7 @@
pm_runtime_reinit(dev);
klist_remove(&dev->p->knode_driver);
+ device_pm_check_callbacks(dev);
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_UNBOUND_DRIVER,
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index 02812bc..93ed14c 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -14,6 +14,8 @@
#include <linux/acpi.h>
#include <linux/pm_domain.h>
+#include "power.h"
+
/**
* dev_pm_get_subsys_data - Create or refcount power.subsys_data for device.
* @dev: Device to handle.
@@ -147,5 +149,6 @@
WARN(device_is_bound(dev),
"PM domains can only be changed for unbound devices\n");
dev->pm_domain = pd;
+ device_pm_check_callbacks(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_domain_set);
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index abbac6f..33a5f4b 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -20,6 +20,8 @@
#include <linux/suspend.h>
#include <linux/export.h>
+#include "power.h"
+
#define GENPD_RETRY_MAX_MS 250 /* Approximate */
#define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 9d626ac..6e7c3cc 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -125,6 +125,7 @@
{
pr_debug("PM: Adding info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
+ device_pm_check_callbacks(dev);
mutex_lock(&dpm_list_mtx);
if (dev->parent && dev->parent->power.is_prepared)
dev_warn(dev, "parent %s should not be sleeping\n",
@@ -147,6 +148,7 @@
mutex_unlock(&dpm_list_mtx);
device_wakeup_disable(dev);
pm_runtime_remove(dev);
+ device_pm_check_callbacks(dev);
}
/**
@@ -1572,6 +1574,11 @@
dev->power.wakeup_path = device_may_wakeup(dev);
+ if (dev->power.no_pm_callbacks) {
+ ret = 1; /* Let device go direct_complete */
+ goto unlock;
+ }
+
if (dev->pm_domain) {
info = "preparing power domain ";
callback = dev->pm_domain->ops.prepare;
@@ -1594,6 +1601,7 @@
if (callback)
ret = callback(dev);
+unlock:
device_unlock(dev);
if (ret < 0) {
@@ -1736,3 +1744,30 @@
device_pm_unlock();
}
EXPORT_SYMBOL_GPL(dpm_for_each_dev);
+
+static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
+{
+ if (!ops)
+ return true;
+
+ return !ops->prepare &&
+ !ops->suspend &&
+ !ops->suspend_late &&
+ !ops->suspend_noirq &&
+ !ops->resume_noirq &&
+ !ops->resume_early &&
+ !ops->resume &&
+ !ops->complete;
+}
+
+void device_pm_check_callbacks(struct device *dev)
+{
+ spin_lock_irq(&dev->power.lock);
+ dev->power.no_pm_callbacks =
+ (!dev->bus || pm_ops_is_empty(dev->bus->pm)) &&
+ (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
+ (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
+ (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
+ (!dev->driver || pm_ops_is_empty(dev->driver->pm));
+ spin_unlock_irq(&dev->power.lock);
+}
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index 8b06193..50e30e7 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -125,6 +125,7 @@
extern void device_pm_move_before(struct device *, struct device *);
extern void device_pm_move_after(struct device *, struct device *);
extern void device_pm_move_last(struct device *);
+extern void device_pm_check_callbacks(struct device *dev);
#else /* !CONFIG_PM_SLEEP */
@@ -143,6 +144,8 @@
struct device *devb) {}
static inline void device_pm_move_last(struct device *dev) {}
+static inline void device_pm_check_callbacks(struct device *dev) {}
+
#endif /* !CONFIG_PM_SLEEP */
static inline void device_pm_init(struct device *dev)