Merge branch 'pm-core'

* pm-core:
  ACPI / PM: Take SMART_SUSPEND driver flag into account
  PCI / PM: Take SMART_SUSPEND driver flag into account
  PCI / PM: Drop unnecessary invocations of pcibios_pm_ops callbacks
  PM / core: Add SMART_SUSPEND driver flag
  PCI / PM: Use the NEVER_SKIP driver flag
  PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags
  PM / core: Convert timers to use timer_setup()
  PM / core: Fix kerneldoc comments of four functions
  PM / core: Drop legacy class suspend/resume operations

Documentation/driver-api/pm/devices.rst

@@ -354,6 +354,20 @@ the phases are: ``prepare``, ``suspend``, ``suspend_late``, ``suspend_noirq``.
 	is because all such devices are initially set to runtime-suspended with
 	runtime PM disabled.
 
+	This feature also can be controlled by device drivers by using the
+	``DPM_FLAG_NEVER_SKIP`` and ``DPM_FLAG_SMART_PREPARE`` driver power
+	management flags.  [Typically, they are set at the time the driver is
+	probed against the device in question by passing them to the
+	:c:func:`dev_pm_set_driver_flags` helper function.]  If the first of
+	these flags is set, the PM core will not apply the direct-complete
+	procedure described above to the given device and, consequenty, to any
+	of its ancestors.  The second flag, when set, informs the middle layer
+	code (bus types, device types, PM domains, classes) that it should take
+	the return value of the ``->prepare`` callback provided by the driver
+	into account and it may only return a positive value from its own
+	``->prepare`` callback if the driver's one also has returned a positive
+	value.
+
     2.	The ``->suspend`` methods should quiesce the device to stop it from
 	performing I/O.  They also may save the device registers and put it into
 	the appropriate low-power state, depending on the bus type the device is
@@ -752,6 +766,26 @@ the state of devices (possibly except for resuming them from runtime suspend)
 from their ``->prepare`` and ``->suspend`` callbacks (or equivalent) *before*
 invoking device drivers' ``->suspend`` callbacks (or equivalent).
 
+Some bus types and PM domains have a policy to resume all devices from runtime
+suspend upfront in their ``->suspend`` callbacks, but that may not be really
+necessary if the driver of the device can cope with runtime-suspended devices.
+The driver can indicate that by setting ``DPM_FLAG_SMART_SUSPEND`` in
+:c:member:`power.driver_flags` at the probe time, by passing it to the
+:c:func:`dev_pm_set_driver_flags` helper.  That also may cause middle-layer code
+(bus types, PM domains etc.) to skip the ``->suspend_late`` and
+``->suspend_noirq`` callbacks provided by the driver if the device remains in
+runtime suspend at the beginning of the ``suspend_late`` phase of system-wide
+suspend (or in the ``poweroff_late`` phase of hibernation), when runtime PM
+has been disabled for it, under the assumption that its state should not change
+after that point until the system-wide transition is over.  If that happens, the
+driver's system-wide resume callbacks, if present, may still be invoked during
+the subsequent system-wide resume transition and the device's runtime power
+management status may be set to "active" before enabling runtime PM for it,
+so the driver must be prepared to cope with the invocation of its system-wide
+resume callbacks back-to-back with its ``->runtime_suspend`` one (without the
+intervening ``->runtime_resume`` and so on) and the final state of the device
+must reflect the "active" status for runtime PM in that case.
+
 During system-wide resume from a sleep state it's easiest to put devices into
 the full-power state, as explained in :file:`Documentation/power/runtime_pm.txt`.
 Refer to that document for more information regarding this particular issue as

Documentation/power/pci.txt

@@ -961,6 +961,39 @@ dev_pm_ops to indicate that one suspend routine is to be pointed to by the
 .suspend(), .freeze(), and .poweroff() members and one resume routine is to
 be pointed to by the .resume(), .thaw(), and .restore() members.
 
+3.1.19. Driver Flags for Power Management
+
+The PM core allows device drivers to set flags that influence the handling of
+power management for the devices by the core itself and by middle layer code
+including the PCI bus type.  The flags should be set once at the driver probe
+time with the help of the dev_pm_set_driver_flags() function and they should not
+be updated directly afterwards.
+
+The DPM_FLAG_NEVER_SKIP flag prevents the PM core from using the direct-complete
+mechanism allowing device suspend/resume callbacks to be skipped if the device
+is in runtime suspend when the system suspend starts.  That also affects all of
+the ancestors of the device, so this flag should only be used if absolutely
+necessary.
+
+The DPM_FLAG_SMART_PREPARE flag instructs the PCI bus type to only return a
+positive value from pci_pm_prepare() if the ->prepare callback provided by the
+driver of the device returns a positive value.  That allows the driver to opt
+out from using the direct-complete mechanism dynamically.
+
+The DPM_FLAG_SMART_SUSPEND flag tells the PCI bus type that from the driver's
+perspective the device can be safely left in runtime suspend during system
+suspend.  That causes pci_pm_suspend(), pci_pm_freeze() and pci_pm_poweroff()
+to skip resuming the device from runtime suspend unless there are PCI-specific
+reasons for doing that.  Also, it causes pci_pm_suspend_late/noirq(),
+pci_pm_freeze_late/noirq() and pci_pm_poweroff_late/noirq() to return early
+if the device remains in runtime suspend in the beginning of the "late" phase
+of the system-wide transition under way.  Moreover, if the device is in
+runtime suspend in pci_pm_resume_noirq() or pci_pm_restore_noirq(), its runtime
+power management status will be changed to "active" (as it is going to be put
+into D0 going forward), but if it is in runtime suspend in pci_pm_thaw_noirq(),
+the function will set the power.direct_complete flag for it (to make the PM core
+skip the subsequent "thaw" callbacks for it) and return.
+
 3.2. Device Runtime Power Management
 ------------------------------------
 In addition to providing device power management callbacks PCI device drivers

drivers/acpi/acpi_lpss.c

@@ -849,8 +849,12 @@ static int acpi_lpss_resume(struct device *dev)
 #ifdef CONFIG_PM_SLEEP
 static int acpi_lpss_suspend_late(struct device *dev)
 {
-	int ret = pm_generic_suspend_late(dev);
+	int ret;
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
 
+	ret = pm_generic_suspend_late(dev);
 	return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
 }
 
@@ -889,10 +893,17 @@ static struct dev_pm_domain acpi_lpss_pm_domain = {
 		.complete = acpi_subsys_complete,
 		.suspend = acpi_subsys_suspend,
 		.suspend_late = acpi_lpss_suspend_late,
+		.suspend_noirq = acpi_subsys_suspend_noirq,
+		.resume_noirq = acpi_subsys_resume_noirq,
 		.resume_early = acpi_lpss_resume_early,
 		.freeze = acpi_subsys_freeze,
+		.freeze_late = acpi_subsys_freeze_late,
+		.freeze_noirq = acpi_subsys_freeze_noirq,
+		.thaw_noirq = acpi_subsys_thaw_noirq,
 		.poweroff = acpi_subsys_suspend,
 		.poweroff_late = acpi_lpss_suspend_late,
+		.poweroff_noirq = acpi_subsys_suspend_noirq,
+		.restore_noirq = acpi_subsys_resume_noirq,
 		.restore_early = acpi_lpss_resume_early,
 #endif
 		.runtime_suspend = acpi_lpss_runtime_suspend,

drivers/acpi/device_pm.c

@@ -939,7 +939,8 @@ static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
 	u32 sys_target = acpi_target_system_state();
 	int ret, state;
 
-	if (device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
+	if (!pm_runtime_suspended(dev) || !adev ||
+	    device_may_wakeup(dev) != !!adev->wakeup.prepare_count)
 		return true;
 
 	if (sys_target == ACPI_STATE_S0)
@@ -962,14 +963,16 @@ static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
 int acpi_subsys_prepare(struct device *dev)
 {
 	struct acpi_device *adev = ACPI_COMPANION(dev);
-	int ret;
 
-	ret = pm_generic_prepare(dev);
-	if (ret < 0)
-		return ret;
+	if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
+		int ret = dev->driver->pm->prepare(dev);
 
-	if (!adev || !pm_runtime_suspended(dev))
-		return 0;
+		if (ret < 0)
+			return ret;
+
+		if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
+			return 0;
+	}
 
 	return !acpi_dev_needs_resume(dev, adev);
 }
@@ -996,12 +999,17 @@ EXPORT_SYMBOL_GPL(acpi_subsys_complete);
  * acpi_subsys_suspend - Run the device driver's suspend callback.
  * @dev: Device to handle.
  *
- * Follow PCI and resume devices suspended at run time before running their
- * system suspend callbacks.
+ * Follow PCI and resume devices from runtime suspend before running their
+ * system suspend callbacks, unless the driver can cope with runtime-suspended
+ * devices during system suspend and there are no ACPI-specific reasons for
+ * resuming them.
  */
 int acpi_subsys_suspend(struct device *dev)
 {
-	pm_runtime_resume(dev);
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
+	    acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
+		pm_runtime_resume(dev);
+
 	return pm_generic_suspend(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
@@ -1015,11 +1023,47 @@ EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
  */
 int acpi_subsys_suspend_late(struct device *dev)
 {
-	int ret = pm_generic_suspend_late(dev);
+	int ret;
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	ret = pm_generic_suspend_late(dev);
 	return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
 
+/**
+ * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
+ * @dev: Device to suspend.
+ */
+int acpi_subsys_suspend_noirq(struct device *dev)
+{
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	return pm_generic_suspend_noirq(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
+
+/**
+ * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
+ * @dev: Device to handle.
+ */
+int acpi_subsys_resume_noirq(struct device *dev)
+{
+	/*
+	 * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
+	 * during system suspend, so update their runtime PM status to "active"
+	 * as they will be put into D0 going forward.
+	 */
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		pm_runtime_set_active(dev);
+
+	return pm_generic_resume_noirq(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_resume_noirq);
+
 /**
  * acpi_subsys_resume_early - Resume device using ACPI.
  * @dev: Device to Resume.
@@ -1047,11 +1091,60 @@ int acpi_subsys_freeze(struct device *dev)
 	 * runtime-suspended devices should not be touched during freeze/thaw
 	 * transitions.
 	 */
-	pm_runtime_resume(dev);
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))
+		pm_runtime_resume(dev);
+
 	return pm_generic_freeze(dev);
 }
 EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
 
+/**
+ * acpi_subsys_freeze_late - Run the device driver's "late" freeze callback.
+ * @dev: Device to handle.
+ */
+int acpi_subsys_freeze_late(struct device *dev)
+{
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	return pm_generic_freeze_late(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_freeze_late);
+
+/**
+ * acpi_subsys_freeze_noirq - Run the device driver's "noirq" freeze callback.
+ * @dev: Device to handle.
+ */
+int acpi_subsys_freeze_noirq(struct device *dev)
+{
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	return pm_generic_freeze_noirq(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_freeze_noirq);
+
+/**
+ * acpi_subsys_thaw_noirq - Run the device driver's "noirq" thaw callback.
+ * @dev: Device to handle.
+ */
+int acpi_subsys_thaw_noirq(struct device *dev)
+{
+	/*
+	 * If the device is in runtime suspend, the "thaw" code may not work
+	 * correctly with it, so skip the driver callback and make the PM core
+	 * skip all of the subsequent "thaw" callbacks for the device.
+	 */
+	if (dev_pm_smart_suspend_and_suspended(dev)) {
+		dev->power.direct_complete = true;
+		return 0;
+	}
+
+	return pm_generic_thaw_noirq(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_thaw_noirq);
 #endif /* CONFIG_PM_SLEEP */
 
 static struct dev_pm_domain acpi_general_pm_domain = {
@@ -1063,10 +1156,17 @@ static struct dev_pm_domain acpi_general_pm_domain = {
 		.complete = acpi_subsys_complete,
 		.suspend = acpi_subsys_suspend,
 		.suspend_late = acpi_subsys_suspend_late,
+		.suspend_noirq = acpi_subsys_suspend_noirq,
+		.resume_noirq = acpi_subsys_resume_noirq,
 		.resume_early = acpi_subsys_resume_early,
 		.freeze = acpi_subsys_freeze,
+		.freeze_late = acpi_subsys_freeze_late,
+		.freeze_noirq = acpi_subsys_freeze_noirq,
+		.thaw_noirq = acpi_subsys_thaw_noirq,
 		.poweroff = acpi_subsys_suspend,
 		.poweroff_late = acpi_subsys_suspend_late,
+		.poweroff_noirq = acpi_subsys_suspend_noirq,
+		.restore_noirq = acpi_subsys_resume_noirq,
 		.restore_early = acpi_subsys_resume_early,
 #endif
 	},

drivers/base/dd.c

@@ -464,6 +464,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	if (dev->pm_domain && dev->pm_domain->dismiss)
 		dev->pm_domain->dismiss(dev);
 	pm_runtime_reinit(dev);
+	dev_pm_set_driver_flags(dev, 0);
 
 	switch (ret) {
 	case -EPROBE_DEFER:
@@ -869,6 +870,7 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 		if (dev->pm_domain && dev->pm_domain->dismiss)
 			dev->pm_domain->dismiss(dev);
 		pm_runtime_reinit(dev);
+		dev_pm_set_driver_flags(dev, 0);
 
 		klist_remove(&dev->p->knode_driver);
 		device_pm_check_callbacks(dev);