Merge branches 'pm-pci' and 'pm-core'
* pm-pci:
PCI / PM: Fix small typo in documentation
PCI / PM: constify pci_platform_pm_ops structure
* pm-core:
PM / core: fix typo in documentation
PM / runtime: Add new helper for conditional usage count incrementation
MAINTAINERS: Add an entry for the PM core
PM / runtime: Re-init runtime PM states at probe error and driver unbind
PM / sleep: prohibit devices probing during suspend/hibernation
diff --git a/Documentation/power/pci.txt b/Documentation/power/pci.txt
index b0e911e..4455888 100644
--- a/Documentation/power/pci.txt
+++ b/Documentation/power/pci.txt
@@ -999,7 +999,7 @@
It is important to remember that the driver's runtime_suspend() callback
may be executed right after the usage counter has been decremented, because
-user space may already have cuased the pm_runtime_allow() helper function
+user space may already have caused the pm_runtime_allow() helper function
unblocking the runtime PM of the device to run via sysfs, so the driver must
be prepared to cope with that.
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 0784bc3..7328cf8 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -371,6 +371,12 @@
- increment the device's usage counter, run pm_runtime_resume(dev) and
return its result
+ int pm_runtime_get_if_in_use(struct device *dev);
+ - return -EINVAL if 'power.disable_depth' is nonzero; otherwise, if the
+ runtime PM status is RPM_ACTIVE and the runtime PM usage counter is
+ nonzero, increment the counter and return 1; otherwise return 0 without
+ changing the counter
+
void pm_runtime_put_noidle(struct device *dev);
- decrement the device's usage counter
diff --git a/MAINTAINERS b/MAINTAINERS
index 233f834..ce97e97 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8447,6 +8447,17 @@
F: include/linux/timer*
F: kernel/time/*timer*
+POWER MANAGEMENT CORE
+M: "Rafael J. Wysocki" <rjw@rjwysocki.net>
+L: linux-pm@vger.kernel.org
+T: git git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
+S: Supported
+F: drivers/base/power/
+F: include/linux/pm.h
+F: include/linux/pm_*
+F: include/linux/powercap.h
+F: drivers/powercap/
+
POWER SUPPLY CLASS/SUBSYSTEM and DRIVERS
M: Sebastian Reichel <sre@kernel.org>
M: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 1782f3a..e05db38 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -131,6 +131,8 @@
extern char *make_class_name(const char *name, struct kobject *kobj);
extern int devres_release_all(struct device *dev);
+extern void device_block_probing(void);
+extern void device_unblock_probing(void);
/* /sys/devices directory */
extern struct kset *devices_kset;
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 0369704..7399be7 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -55,6 +55,13 @@
static atomic_t deferred_trigger_count = ATOMIC_INIT(0);
/*
+ * In some cases, like suspend to RAM or hibernation, It might be reasonable
+ * to prohibit probing of devices as it could be unsafe.
+ * Once defer_all_probes is true all drivers probes will be forcibly deferred.
+ */
+static bool defer_all_probes;
+
+/*
* deferred_probe_work_func() - Retry probing devices in the active list.
*/
static void deferred_probe_work_func(struct work_struct *work)
@@ -172,6 +179,30 @@
}
/**
+ * device_block_probing() - Block/defere device's probes
+ *
+ * It will disable probing of devices and defer their probes instead.
+ */
+void device_block_probing(void)
+{
+ defer_all_probes = true;
+ /* sync with probes to avoid races. */
+ wait_for_device_probe();
+}
+
+/**
+ * device_unblock_probing() - Unblock/enable device's probes
+ *
+ * It will restore normal behavior and trigger re-probing of deferred
+ * devices.
+ */
+void device_unblock_probing(void)
+{
+ defer_all_probes = false;
+ driver_deferred_probe_trigger();
+}
+
+/**
* deferred_probe_initcall() - Enable probing of deferred devices
*
* We don't want to get in the way when the bulk of drivers are getting probed.
@@ -280,9 +311,20 @@
static int really_probe(struct device *dev, struct device_driver *drv)
{
- int ret = 0;
+ int ret = -EPROBE_DEFER;
int local_trigger_count = atomic_read(&deferred_trigger_count);
+ if (defer_all_probes) {
+ /*
+ * Value of defer_all_probes can be set only by
+ * device_defer_all_probes_enable() which, in turn, will call
+ * wait_for_device_probe() right after that to avoid any races.
+ */
+ dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
+ driver_deferred_probe_add(dev);
+ return ret;
+ }
+
atomic_inc(&probe_count);
pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
drv->bus->name, __func__, drv->name, dev_name(dev));
@@ -347,6 +389,7 @@
dev_set_drvdata(dev, NULL);
if (dev->pm_domain && dev->pm_domain->dismiss)
dev->pm_domain->dismiss(dev);
+ pm_runtime_reinit(dev);
switch (ret) {
case -EPROBE_DEFER:
@@ -400,6 +443,10 @@
*/
void wait_for_device_probe(void)
{
+ /* wait for the deferred probe workqueue to finish */
+ if (driver_deferred_probe_enable)
+ flush_workqueue(deferred_wq);
+
/* wait for the known devices to complete their probing */
wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
async_synchronize_full();
@@ -702,6 +749,7 @@
dev_set_drvdata(dev, NULL);
if (dev->pm_domain && dev->pm_domain->dismiss)
dev->pm_domain->dismiss(dev);
+ pm_runtime_reinit(dev);
klist_remove(&dev->p->knode_driver);
if (dev->bus)
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index f32b802..f48e333 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -112,7 +112,7 @@
/**
* dev_pm_domain_detach - Detach a device from its PM domain.
- * @dev: Device to attach.
+ * @dev: Device to detach.
* @power_off: Used to indicate whether we should power off the device.
*
* This functions will reverse the actions from dev_pm_domain_attach() and thus
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 1710c26..9d626ac 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -963,6 +963,9 @@
}
list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
+
+ /* Allow device probing and trigger re-probing of deferred devices */
+ device_unblock_probing();
trace_suspend_resume(TPS("dpm_complete"), state.event, false);
}
@@ -1624,6 +1627,20 @@
trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
might_sleep();
+ /*
+ * Give a chance for the known devices to complete their probes, before
+ * disable probing of devices. This sync point is important at least
+ * at boot time + hibernation restore.
+ */
+ wait_for_device_probe();
+ /*
+ * It is unsafe if probing of devices will happen during suspend or
+ * hibernation and system behavior will be unpredictable in this case.
+ * So, let's prohibit device's probing here and defer their probes
+ * instead. The normal behavior will be restored in dpm_complete().
+ */
+ device_block_probing();
+
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.next);
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index 998fa6b..8b06193 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -18,6 +18,7 @@
}
extern void pm_runtime_init(struct device *dev);
+extern void pm_runtime_reinit(struct device *dev);
extern void pm_runtime_remove(struct device *dev);
struct wake_irq {
@@ -84,6 +85,7 @@
}
static inline void pm_runtime_init(struct device *dev) {}
+static inline void pm_runtime_reinit(struct device *dev) {}
static inline void pm_runtime_remove(struct device *dev) {}
static inline int dpm_sysfs_add(struct device *dev) { return 0; }
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index e1a10a0..4c70550 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -966,6 +966,30 @@
EXPORT_SYMBOL_GPL(__pm_runtime_resume);
/**
+ * pm_runtime_get_if_in_use - Conditionally bump up the device's usage counter.
+ * @dev: Device to handle.
+ *
+ * Return -EINVAL if runtime PM is disabled for the device.
+ *
+ * If that's not the case and if the device's runtime PM status is RPM_ACTIVE
+ * and the runtime PM usage counter is nonzero, increment the counter and
+ * return 1. Otherwise return 0 without changing the counter.
+ */
+int pm_runtime_get_if_in_use(struct device *dev)
+{
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = dev->power.disable_depth > 0 ? -EINVAL :
+ dev->power.runtime_status == RPM_ACTIVE
+ && atomic_inc_not_zero(&dev->power.usage_count);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
+
+/**
* __pm_runtime_set_status - Set runtime PM status of a device.
* @dev: Device to handle.
* @status: New runtime PM status of the device.
@@ -1390,18 +1414,32 @@
}
/**
+ * pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
+ * @dev: Device object to re-initialize.
+ */
+void pm_runtime_reinit(struct device *dev)
+{
+ if (!pm_runtime_enabled(dev)) {
+ if (dev->power.runtime_status == RPM_ACTIVE)
+ pm_runtime_set_suspended(dev);
+ if (dev->power.irq_safe) {
+ spin_lock_irq(&dev->power.lock);
+ dev->power.irq_safe = 0;
+ spin_unlock_irq(&dev->power.lock);
+ if (dev->parent)
+ pm_runtime_put(dev->parent);
+ }
+ }
+}
+
+/**
* pm_runtime_remove - Prepare for removing a device from device hierarchy.
* @dev: Device object being removed from device hierarchy.
*/
void pm_runtime_remove(struct device *dev)
{
__pm_runtime_disable(dev, false);
-
- /* Change the status back to 'suspended' to match the initial status. */
- if (dev->power.runtime_status == RPM_ACTIVE)
- pm_runtime_set_suspended(dev);
- if (dev->power.irq_safe && dev->parent)
- pm_runtime_put(dev->parent);
+ pm_runtime_reinit(dev);
}
/**
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index a32ba75..8400f80 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -529,7 +529,7 @@
return !!adev->power.flags.dsw_present;
}
-static struct pci_platform_pm_ops acpi_pci_platform_pm = {
+static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
.is_manageable = acpi_pci_power_manageable,
.set_state = acpi_pci_set_power_state,
.choose_state = acpi_pci_choose_state,
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 314db8c..d1a7105 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -527,9 +527,9 @@
pci_update_resource(dev, i);
}
-static struct pci_platform_pm_ops *pci_platform_pm;
+static const struct pci_platform_pm_ops *pci_platform_pm;
-int pci_set_platform_pm(struct pci_platform_pm_ops *ops)
+int pci_set_platform_pm(const struct pci_platform_pm_ops *ops)
{
if (!ops->is_manageable || !ops->set_state || !ops->choose_state
|| !ops->sleep_wake)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index d390fc1..f6f151a 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -68,7 +68,7 @@
bool (*need_resume)(struct pci_dev *dev);
};
-int pci_set_platform_pm(struct pci_platform_pm_ops *ops);
+int pci_set_platform_pm(const struct pci_platform_pm_ops *ops);
void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
void pci_power_up(struct pci_dev *dev);
void pci_disable_enabled_device(struct pci_dev *dev);
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 3bdbb41..7af093d 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -39,6 +39,7 @@
extern int __pm_runtime_idle(struct device *dev, int rpmflags);
extern int __pm_runtime_suspend(struct device *dev, int rpmflags);
extern int __pm_runtime_resume(struct device *dev, int rpmflags);
+extern int pm_runtime_get_if_in_use(struct device *dev);
extern int pm_schedule_suspend(struct device *dev, unsigned int delay);
extern int __pm_runtime_set_status(struct device *dev, unsigned int status);
extern int pm_runtime_barrier(struct device *dev);
@@ -143,6 +144,10 @@
{
return -ENOSYS;
}
+static inline int pm_runtime_get_if_in_use(struct device *dev)
+{
+ return -EINVAL;
+}
static inline int __pm_runtime_set_status(struct device *dev,
unsigned int status) { return 0; }
static inline int pm_runtime_barrier(struct device *dev) { return 0; }