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

···
 	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
···
 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`.

Documentation/power/pci.txt

···
 .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

···
 #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));
 }
 
···
 		.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

···
 	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)
···
 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);
 }
···
  * 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);
···
  */
 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.
···
 	 * 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 = {
···
 		.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

···
 	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:
···
 		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);

drivers/base/power/main.c

···
 /*------------------------- Resume routines -------------------------*/
 
 /**
- * device_resume_noirq - Execute an "early resume" callback for given device.
+ * device_resume_noirq - Execute a "noirq resume" callback for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
  * @async: If true, the device is being resumed asynchronously.
···
 		goto Driver;
 	}
 
-	if (dev->class) {
-		if (dev->class->pm) {
-			info = "class ";
-			callback = pm_op(dev->class->pm, state);
-			goto Driver;
-		} else if (dev->class->resume) {
-			info = "legacy class ";
-			callback = dev->class->resume;
-			goto End;
-		}
+	if (dev->class && dev->class->pm) {
+		info = "class ";
+		callback = pm_op(dev->class->pm, state);
+		goto Driver;
 	}
 
 	if (dev->bus) {
···
 }
 
 /**
- * device_suspend_noirq - Execute a "late suspend" callback for given device.
+ * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
  * @async: If true, the device is being suspended asynchronously.
···
 }
 
 /**
- * device_suspend_late - Execute a "late suspend" callback for given device.
+ * __device_suspend_late - Execute a "late suspend" callback for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
  * @async: If true, the device is being suspended asynchronously.
···
 }
 
 /**
- * device_suspend - Execute "suspend" callbacks for given device.
+ * __device_suspend - Execute "suspend" callbacks for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
  * @async: If true, the device is being suspended asynchronously.
···
 		goto Run;
 	}
 
-	if (dev->class) {
-		if (dev->class->pm) {
-			info = "class ";
-			callback = pm_op(dev->class->pm, state);
-			goto Run;
-		} else if (dev->class->suspend) {
-			pm_dev_dbg(dev, state, "legacy class ");
-			error = legacy_suspend(dev, state, dev->class->suspend,
-						"legacy class ");
-			goto End;
-		}
+	if (dev->class && dev->class->pm) {
+		info = "class ";
+		callback = pm_op(dev->class->pm, state);
+		goto Run;
 	}
 
 	if (dev->bus) {
···
 	if (dev->power.syscore)
 		return 0;
 
+	WARN_ON(dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
+		!pm_runtime_enabled(dev));
+
 	/*
 	 * If a device's parent goes into runtime suspend at the wrong time,
 	 * it won't be possible to resume the device.  To prevent this we
···
 	 * applies to suspend transitions, however.
 	 */
 	spin_lock_irq(&dev->power.lock);
-	dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND;
+	dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
+		pm_runtime_suspended(dev) && ret > 0 &&
+		!dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
 	spin_unlock_irq(&dev->power.lock);
 	return 0;
 }
···
 	dev->power.no_pm_callbacks =
 		(!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
 		 !dev->bus->suspend && !dev->bus->resume)) &&
-		(!dev->class || (pm_ops_is_empty(dev->class->pm) &&
-		 !dev->class->suspend && !dev->class->resume)) &&
+		(!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) &&
 		 !dev->driver->suspend && !dev->driver->resume));
 	spin_unlock_irq(&dev->power.lock);
+}
+
+bool dev_pm_smart_suspend_and_suspended(struct device *dev)
+{
+	return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
+		pm_runtime_status_suspended(dev);
 }

drivers/base/power/runtime.c

···
  *
  * Check if the time is right and queue a suspend request.
  */
-static void pm_suspend_timer_fn(unsigned long data)
+static void pm_suspend_timer_fn(struct timer_list *t)
 {
-	struct device *dev = (struct device *)data;
+	struct device *dev = from_timer(dev, t, power.suspend_timer);
 	unsigned long flags;
 	unsigned long expires;
 
···
 	INIT_WORK(&dev->power.work, pm_runtime_work);
 
 	dev->power.timer_expires = 0;
-	setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
-			(unsigned long)dev);
+	timer_setup(&dev->power.suspend_timer, pm_suspend_timer_fn, 0);
 
 	init_waitqueue_head(&dev->power.wait_queue);
 }

drivers/base/power/wakeup.c

···
 
 static DEFINE_SPINLOCK(events_lock);
 
-static void pm_wakeup_timer_fn(unsigned long data);
+static void pm_wakeup_timer_fn(struct timer_list *t);
 
 static LIST_HEAD(wakeup_sources);
 
···
 		return;
 
 	spin_lock_init(&ws->lock);
-	setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
+	timer_setup(&ws->timer, pm_wakeup_timer_fn, 0);
 	ws->active = false;
 	ws->last_time = ktime_get();
 
···
 	 * Use timer struct to check if the given source is initialized
 	 * by wakeup_source_add.
 	 */
-	return ws->timer.function != pm_wakeup_timer_fn ||
-		   ws->timer.data != (unsigned long)ws;
+	return ws->timer.function != (TIMER_FUNC_TYPE)pm_wakeup_timer_fn;
 }
 
 /*
···
  * in @data if it is currently active and its timer has not been canceled and
  * the expiration time of the timer is not in future.
  */
-static void pm_wakeup_timer_fn(unsigned long data)
+static void pm_wakeup_timer_fn(struct timer_list *t)
 {
-	struct wakeup_source *ws = (struct wakeup_source *)data;
+	struct wakeup_source *ws = from_timer(ws, t, timer);
 	unsigned long flags;
 
 	spin_lock_irqsave(&ws->lock, flags);

drivers/gpu/drm/i915/i915_drv.c

···
 	 * becaue the HDA driver may require us to enable the audio power
 	 * domain during system suspend.
 	 */
-	pdev->dev_flags |= PCI_DEV_FLAGS_NEEDS_RESUME;
+	dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP);
 
 	ret = i915_driver_init_early(dev_priv, ent);
 	if (ret < 0)

drivers/misc/mei/pci-me.c

···
 	 * MEI requires to resume from runtime suspend mode
 	 * in order to perform link reset flow upon system suspend.
 	 */
-	pdev->dev_flags |= PCI_DEV_FLAGS_NEEDS_RESUME;
+	dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP);
 
 	/*
 	 * ME maps runtime suspend/resume to D0i states,

drivers/misc/mei/pci-txe.c

···
 	 * MEI requires to resume from runtime suspend mode
 	 * in order to perform link reset flow upon system suspend.
 	 */
-	pdev->dev_flags |= PCI_DEV_FLAGS_NEEDS_RESUME;
+	dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NEVER_SKIP);
 
 	/*
 	 * TXE maps runtime suspend/resume to own power gating states,

drivers/pci/pci-driver.c

···
 
 	if (drv && drv->pm && drv->pm->prepare) {
 		int error = drv->pm->prepare(dev);
-		if (error)
+		if (error < 0)
 			return error;
+
+		if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
+			return 0;
 	}
 	return pci_dev_keep_suspended(to_pci_dev(dev));
 }
···
 
 	if (!pm) {
 		pci_pm_default_suspend(pci_dev);
-		goto Fixup;
+		return 0;
 	}
 
 	/*
-	 * PCI devices suspended at run time need to be resumed at this point,
-	 * because in general it is necessary to reconfigure them for system
-	 * suspend.  Namely, if the device is supposed to wake up the system
-	 * from the sleep state, we may need to reconfigure it for this purpose.
-	 * In turn, if the device is not supposed to wake up the system from the
-	 * sleep state, we'll have to prevent it from signaling wake-up.
+	 * PCI devices suspended at run time may need to be resumed at this
+	 * point, because in general it may be necessary to reconfigure them for
+	 * system suspend.  Namely, if the device is expected to wake up the
+	 * system from the sleep state, it may have to be reconfigured for this
+	 * purpose, or if the device is not expected to wake up the system from
+	 * the sleep state, it should be prevented from signaling wakeup events
+	 * going forward.
+	 *
+	 * Also if the driver of the device does not indicate that its system
+	 * suspend callbacks can cope with runtime-suspended devices, it is
+	 * better to resume the device from runtime suspend here.
 	 */
-	pm_runtime_resume(dev);
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
+	    !pci_dev_keep_suspended(pci_dev))
+		pm_runtime_resume(dev);
 
 	pci_dev->state_saved = false;
 	if (pm->suspend) {
···
 		}
 	}
 
- Fixup:
-	pci_fixup_device(pci_fixup_suspend, pci_dev);
-
 	return 0;
+}
+
+static int pci_pm_suspend_late(struct device *dev)
+{
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
+
+	return pm_generic_suspend_late(dev);
 }
 
 static int pci_pm_suspend_noirq(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
 
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_suspend_late(dev, PMSG_SUSPEND);
···
 	struct device_driver *drv = dev->driver;
 	int error = 0;
 
+	/*
+	 * 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 are going to be put into D0 shortly.
+	 */
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		pm_runtime_set_active(dev);
+
 	pci_pm_default_resume_early(pci_dev);
 
 	if (pci_has_legacy_pm_support(pci_dev))
···
 #else /* !CONFIG_SUSPEND */
 
 #define pci_pm_suspend		NULL
+#define pci_pm_suspend_late	NULL
 #define pci_pm_suspend_noirq	NULL
 #define pci_pm_resume		NULL
 #define pci_pm_resume_noirq	NULL
···
 	 * devices should not be touched during freeze/thaw transitions,
 	 * however.
 	 */
-	pm_runtime_resume(dev);
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))
+		pm_runtime_resume(dev);
 
 	pci_dev->state_saved = false;
 	if (pm->freeze) {
···
 			return error;
 	}
 
-	if (pcibios_pm_ops.freeze)
-		return pcibios_pm_ops.freeze(dev);
-
 	return 0;
+}
+
+static int pci_pm_freeze_late(struct device *dev)
+{
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	return pm_generic_freeze_late(dev);;
 }
 
 static int pci_pm_freeze_noirq(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	struct device_driver *drv = dev->driver;
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
 
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_suspend_late(dev, PMSG_FREEZE);
···
 	struct device_driver *drv = dev->driver;
 	int error = 0;
 
+	/*
+	 * If the device is in runtime suspend, the code below may not work
+	 * correctly with it, so skip that code 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;
+	}
+
 	if (pcibios_pm_ops.thaw_noirq) {
 		error = pcibios_pm_ops.thaw_noirq(dev);
 		if (error)
···
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int error = 0;
-
-	if (pcibios_pm_ops.thaw) {
-		error = pcibios_pm_ops.thaw(dev);
-		if (error)
-			return error;
-	}
 
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume(dev);
···
 
 	if (!pm) {
 		pci_pm_default_suspend(pci_dev);
-		goto Fixup;
+		return 0;
 	}
 
 	/* The reason to do that is the same as in pci_pm_suspend(). */
-	pm_runtime_resume(dev);
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
+	    !pci_dev_keep_suspended(pci_dev))
+		pm_runtime_resume(dev);
 
 	pci_dev->state_saved = false;
 	if (pm->poweroff) {
···
 			return error;
 	}
 
- Fixup:
-	pci_fixup_device(pci_fixup_suspend, pci_dev);
-
-	if (pcibios_pm_ops.poweroff)
-		return pcibios_pm_ops.poweroff(dev);
-
 	return 0;
+}
+
+static int pci_pm_poweroff_late(struct device *dev)
+{
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
+
+	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
+
+	return pm_generic_poweroff_late(dev);
 }
 
 static int pci_pm_poweroff_noirq(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	struct device_driver *drv = dev->driver;
+
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		return 0;
 
 	if (pci_has_legacy_pm_support(to_pci_dev(dev)))
 		return pci_legacy_suspend_late(dev, PMSG_HIBERNATE);
···
 	struct device_driver *drv = dev->driver;
 	int error = 0;
 
+	/* This is analogous to the pci_pm_resume_noirq() case. */
+	if (dev_pm_smart_suspend_and_suspended(dev))
+		pm_runtime_set_active(dev);
+
 	if (pcibios_pm_ops.restore_noirq) {
 		error = pcibios_pm_ops.restore_noirq(dev);
 		if (error)
···
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int error = 0;
-
-	if (pcibios_pm_ops.restore) {
-		error = pcibios_pm_ops.restore(dev);
-		if (error)
-			return error;
-	}
 
 	/*
 	 * This is necessary for the hibernation error path in which restore is
···
 #else /* !CONFIG_HIBERNATE_CALLBACKS */
 
 #define pci_pm_freeze		NULL
+#define pci_pm_freeze_late	NULL
 #define pci_pm_freeze_noirq	NULL
 #define pci_pm_thaw		NULL
 #define pci_pm_thaw_noirq	NULL
 #define pci_pm_poweroff		NULL
+#define pci_pm_poweroff_late	NULL
 #define pci_pm_poweroff_noirq	NULL
 #define pci_pm_restore		NULL
 #define pci_pm_restore_noirq	NULL
···
 	.prepare = pci_pm_prepare,
 	.complete = pci_pm_complete,
 	.suspend = pci_pm_suspend,
+	.suspend_late = pci_pm_suspend_late,
 	.resume = pci_pm_resume,
 	.freeze = pci_pm_freeze,
+	.freeze_late = pci_pm_freeze_late,
 	.thaw = pci_pm_thaw,
 	.poweroff = pci_pm_poweroff,
+	.poweroff_late = pci_pm_poweroff_late,
 	.restore = pci_pm_restore,
 	.suspend_noirq = pci_pm_suspend_noirq,
 	.resume_noirq = pci_pm_resume_noirq,

drivers/pci/pci.c

···
 
 	if (!pm_runtime_suspended(dev)
 	    || pci_target_state(pci_dev, wakeup) != pci_dev->current_state
-	    || platform_pci_need_resume(pci_dev)
-	    || (pci_dev->dev_flags & PCI_DEV_FLAGS_NEEDS_RESUME))
+	    || platform_pci_need_resume(pci_dev))
 		return false;
 
 	/*

include/linux/acpi.h

···
 int acpi_subsys_prepare(struct device *dev);
 void acpi_subsys_complete(struct device *dev);
 int acpi_subsys_suspend_late(struct device *dev);
+int acpi_subsys_suspend_noirq(struct device *dev);
+int acpi_subsys_resume_noirq(struct device *dev);
 int acpi_subsys_resume_early(struct device *dev);
 int acpi_subsys_suspend(struct device *dev);
 int acpi_subsys_freeze(struct device *dev);
+int acpi_subsys_freeze_late(struct device *dev);
+int acpi_subsys_freeze_noirq(struct device *dev);
+int acpi_subsys_thaw_noirq(struct device *dev);
 #else
 static inline int acpi_dev_resume_early(struct device *dev) { return 0; }
 static inline int acpi_subsys_prepare(struct device *dev) { return 0; }
 static inline void acpi_subsys_complete(struct device *dev) {}
 static inline int acpi_subsys_suspend_late(struct device *dev) { return 0; }
+static inline int acpi_subsys_suspend_noirq(struct device *dev) { return 0; }
+static inline int acpi_subsys_resume_noirq(struct device *dev) { return 0; }
 static inline int acpi_subsys_resume_early(struct device *dev) { return 0; }
 static inline int acpi_subsys_suspend(struct device *dev) { return 0; }
 static inline int acpi_subsys_freeze(struct device *dev) { return 0; }
+static inline int acpi_subsys_freeze_late(struct device *dev) { return 0; }
+static inline int acpi_subsys_freeze_noirq(struct device *dev) { return 0; }
+static inline int acpi_subsys_thaw_noirq(struct device *dev) { return 0; }
 #endif
 
 #ifdef CONFIG_ACPI

include/linux/device.h

···
  * @devnode:	Callback to provide the devtmpfs.
  * @class_release: Called to release this class.
  * @dev_release: Called to release the device.
- * @suspend:	Used to put the device to sleep mode, usually to a low power
- *		state.
- * @resume:	Used to bring the device from the sleep mode.
  * @shutdown_pre: Called at shut-down time before driver shutdown.
  * @ns_type:	Callbacks so sysfs can detemine namespaces.
  * @namespace:	Namespace of the device belongs to this class.
···
 	void (*class_release)(struct class *class);
 	void (*dev_release)(struct device *dev);
 
-	int (*suspend)(struct device *dev, pm_message_t state);
-	int (*resume)(struct device *dev);
 	int (*shutdown_pre)(struct device *dev);
 
 	const struct kobj_ns_type_operations *ns_type;
···
 #ifdef CONFIG_PM_SLEEP
 	dev->power.syscore = val;
 #endif
+}
+
+static inline void dev_pm_set_driver_flags(struct device *dev, u32 flags)
+{
+	dev->power.driver_flags = flags;
+}
+
+static inline bool dev_pm_test_driver_flags(struct device *dev, u32 flags)
+{
+	return !!(dev->power.driver_flags & flags);
 }
 
 static inline void device_lock(struct device *dev)

include/linux/pci.h

···
 	PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT = (__force pci_dev_flags_t) (1 << 9),
 	/* Do not use FLR even if device advertises PCI_AF_CAP */
 	PCI_DEV_FLAGS_NO_FLR_RESET = (__force pci_dev_flags_t) (1 << 10),
-	/*
-	 * Resume before calling the driver's system suspend hooks, disabling
-	 * the direct_complete optimization.
-	 */
-	PCI_DEV_FLAGS_NEEDS_RESUME = (__force pci_dev_flags_t) (1 << 11),
 	/* Don't use Relaxed Ordering for TLPs directed at this device */
-	PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 12),
+	PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 11),
 };
 
 enum pci_irq_reroute_variant {

include/linux/pm.h

···
 #endif
 };
 
+/*
+ * Driver flags to control system suspend/resume behavior.
+ *
+ * These flags can be set by device drivers at the probe time.  They need not be
+ * cleared by the drivers as the driver core will take care of that.
+ *
+ * NEVER_SKIP: Do not skip system suspend/resume callbacks for the device.
+ * SMART_PREPARE: Check the return value of the driver's ->prepare callback.
+ * SMART_SUSPEND: No need to resume the device from runtime suspend.
+ *
+ * Setting SMART_PREPARE instructs bus types and PM domains which may want
+ * system suspend/resume callbacks to be skipped for the device to return 0 from
+ * their ->prepare callbacks if the driver's ->prepare callback returns 0 (in
+ * other words, the system suspend/resume callbacks can only be skipped for the
+ * device if its driver doesn't object against that).  This flag has no effect
+ * if NEVER_SKIP is set.
+ *
+ * Setting SMART_SUSPEND instructs bus types and PM domains which may want to
+ * runtime resume the device upfront during system suspend that doing so is not
+ * necessary from the driver's perspective.  It also may cause them to skip
+ * invocations of the ->suspend_late and ->suspend_noirq callbacks provided by
+ * the driver if they decide to leave the device in runtime suspend.
+ */
+#define DPM_FLAG_NEVER_SKIP	BIT(0)
+#define DPM_FLAG_SMART_PREPARE	BIT(1)
+#define DPM_FLAG_SMART_SUSPEND	BIT(2)
+
 struct dev_pm_info {
 	pm_message_t		power_state;
 	unsigned int		can_wakeup:1;
···
 	bool			is_late_suspended:1;
 	bool			early_init:1;	/* Owned by the PM core */
 	bool			direct_complete:1;	/* Owned by the PM core */
+	u32			driver_flags;
 	spinlock_t		lock;
 #ifdef CONFIG_PM_SLEEP
 	struct list_head	entry;
···
 extern int pm_generic_poweroff_late(struct device *dev);
 extern int pm_generic_poweroff(struct device *dev);
 extern void pm_generic_complete(struct device *dev);
+
+extern bool dev_pm_smart_suspend_and_suspended(struct device *dev);
 
 #else /* !CONFIG_PM_SLEEP */