1 files changed, 147 insertions, 119 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index c697f2680856..93eac1423585 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -355,17 +355,34 @@ static int pci_legacy_suspend(struct device *dev, pm_message_t state)
 	int i = 0;
 
 	if (drv && drv->suspend) {
+		pci_power_t prev = pci_dev->current_state;
+
+		pci_dev->state_saved = false;
+
 		i = drv->suspend(pci_dev, state);
 		suspend_report_result(drv->suspend, i);
-	} else {
-		pci_save_state(pci_dev);
-		/*
-		 * This is for compatibility with existing code with legacy PM
-		 * support.
-		 */
-		pci_pm_set_unknown_state(pci_dev);
+		if (i)
+			return i;
+
+		if (pci_dev->state_saved)
+			goto Fixup;
+
+		if (pci_dev->current_state != PCI_D0
+		    && pci_dev->current_state != PCI_UNKNOWN) {
+			WARN_ONCE(pci_dev->current_state != prev,
+				"PCI PM: Device state not saved by %pF\n",
+				drv->suspend);
+			goto Fixup;
+		}
 	}
 
+	pci_save_state(pci_dev);
+	/*
+	 * This is for compatibility with existing code with legacy PM support.
+	 */
+	pci_pm_set_unknown_state(pci_dev);
+
+ Fixup:
 	pci_fixup_device(pci_fixup_suspend, pci_dev);
 
 	return i;
@@ -386,108 +403,47 @@ static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
 
 static int pci_legacy_resume_early(struct device *dev)
 {
-	int error = 0;
 	struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * drv = pci_dev->driver;
 
-	pci_fixup_device(pci_fixup_resume_early, pci_dev);
-
-	if (drv && drv->resume_early)
-		error = drv->resume_early(pci_dev);
-	return error;
+	return drv && drv->resume_early ?
+			drv->resume_early(pci_dev) : 0;
 }
 
 static int pci_legacy_resume(struct device *dev)
 {
-	int error;
 	struct pci_dev * pci_dev = to_pci_dev(dev);
 	struct pci_driver * drv = pci_dev->driver;
 
 	pci_fixup_device(pci_fixup_resume, pci_dev);
 
-	if (drv && drv->resume) {
-		error = drv->resume(pci_dev);
-	} else {
-		/* restore the PCI config space */
-		pci_restore_state(pci_dev);
-		error = pci_pm_reenable_device(pci_dev);
-	}
-	return error;
+	return drv && drv->resume ?
+			drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
 }
 
 /* Auxiliary functions used by the new power management framework */
 
-static int pci_restore_standard_config(struct pci_dev *pci_dev)
-{
-	struct pci_dev *parent = pci_dev->bus->self;
-	int error = 0;
-
-	/* Check if the device's bus is operational */
-	if (!parent || parent->current_state == PCI_D0) {
-		pci_restore_state(pci_dev);
-		pci_update_current_state(pci_dev, PCI_D0);
-	} else {
-		dev_warn(&pci_dev->dev, "unable to restore config, "
-			"bridge %s in low power state D%d\n", pci_name(parent),
-			parent->current_state);
-		pci_dev->current_state = PCI_UNKNOWN;
-		error = -EAGAIN;
-	}
-
-	return error;
-}
-
-static bool pci_is_bridge(struct pci_dev *pci_dev)
-{
-	return !!(pci_dev->subordinate);
-}
-
 static void pci_pm_default_resume_noirq(struct pci_dev *pci_dev)
 {
-	if (pci_restore_standard_config(pci_dev))
-		pci_fixup_device(pci_fixup_resume_early, pci_dev);
+	pci_restore_standard_config(pci_dev);
+	pci_dev->state_saved = false;
+	pci_fixup_device(pci_fixup_resume_early, pci_dev);
 }
 
-static int pci_pm_default_resume(struct pci_dev *pci_dev)
+static void pci_pm_default_resume(struct pci_dev *pci_dev)
 {
-	/*
-	 * pci_restore_standard_config() should have been called once already,
-	 * but it would have failed if the device's parent bridge had not been
-	 * in power state D0 at that time.  Check it and try again if necessary.
-	 */
-	if (pci_dev->current_state == PCI_UNKNOWN) {
-		int error = pci_restore_standard_config(pci_dev);
-		if (error)
-			return error;
-	}
-
 	pci_fixup_device(pci_fixup_resume, pci_dev);
 
 	if (!pci_is_bridge(pci_dev))
 		pci_enable_wake(pci_dev, PCI_D0, false);
-
-	return pci_pm_reenable_device(pci_dev);
-}
-
-static void pci_pm_default_suspend_generic(struct pci_dev *pci_dev)
-{
-	/* If device is enabled at this point, disable it */
-	pci_disable_enabled_device(pci_dev);
-	/*
-	 * Save state with interrupts enabled, because in principle the bus the
-	 * device is on may be put into a low power state after this code runs.
-	 */
-	pci_save_state(pci_dev);
 }
 
 static void pci_pm_default_suspend(struct pci_dev *pci_dev)
 {
-	pci_pm_default_suspend_generic(pci_dev);
-
+	/* Disable non-bridge devices without PM support */
 	if (!pci_is_bridge(pci_dev))
-		pci_prepare_to_sleep(pci_dev);
-
-	pci_fixup_device(pci_fixup_suspend, pci_dev);
+		pci_disable_enabled_device(pci_dev);
+	pci_save_state(pci_dev);
 }
 
 static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
@@ -532,21 +488,49 @@ static void pci_pm_complete(struct device *dev)
 static int pci_pm_suspend(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct device_driver *drv = dev->driver;
-	int error = 0;
+	struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_suspend(dev, PMSG_SUSPEND);
 
-	if (drv && drv->pm && drv->pm->suspend) {
-		error = drv->pm->suspend(dev);
-		suspend_report_result(drv->pm->suspend, error);
+	if (!pm) {
+		pci_pm_default_suspend(pci_dev);
+		goto Fixup;
 	}
 
-	if (!error)
-		pci_pm_default_suspend(pci_dev);
+	pci_dev->state_saved = false;
 
-	return error;
+	if (pm->suspend) {
+		pci_power_t prev = pci_dev->current_state;
+		int error;
+
+		error = pm->suspend(dev);
+		suspend_report_result(pm->suspend, error);
+		if (error)
+			return error;
+
+		if (pci_dev->state_saved)
+			goto Fixup;
+
+		if (pci_dev->current_state != PCI_D0
+		    && pci_dev->current_state != PCI_UNKNOWN) {
+			WARN_ONCE(pci_dev->current_state != prev,
+				"PCI PM: State of device not saved by %pF\n",
+				pm->suspend);
+			goto Fixup;
+		}
+	}
+
+	if (!pci_dev->state_saved) {
+		pci_save_state(pci_dev);
+		if (!pci_is_bridge(pci_dev))
+			pci_prepare_to_sleep(pci_dev);
+	}
+
+ Fixup:
+	pci_fixup_device(pci_fixup_suspend, pci_dev);
+
+	return 0;
 }
 
 static int pci_pm_suspend_noirq(struct device *dev)
@@ -575,11 +559,11 @@ static int pci_pm_resume_noirq(struct device *dev)
 	struct device_driver *drv = dev->driver;
 	int error = 0;
 
+	pci_pm_default_resume_noirq(pci_dev);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume_early(dev);
 
-	pci_pm_default_resume_noirq(pci_dev);
-
 	if (drv && drv->pm && drv->pm->resume_noirq)
 		error = drv->pm->resume_noirq(dev);
 
@@ -589,18 +573,29 @@ static int pci_pm_resume_noirq(struct device *dev)
 static int pci_pm_resume(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct device_driver *drv = dev->driver;
+	struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int error = 0;
 
+	/*
+	 * This is necessary for the suspend error path in which resume is
+	 * called without restoring the standard config registers of the device.
+	 */
+	if (pci_dev->state_saved)
+		pci_restore_standard_config(pci_dev);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume(dev);
 
-	error = pci_pm_default_resume(pci_dev);
+	pci_pm_default_resume(pci_dev);
 
-	if (!error && drv && drv->pm && drv->pm->resume)
-		error = drv->pm->resume(dev);
+	if (pm) {
+		if (pm->resume)
+			error = pm->resume(dev);
+	} else {
+		pci_pm_reenable_device(pci_dev);
+	}
 
-	return error;
+	return 0;
 }
 
 #else /* !CONFIG_SUSPEND */
@@ -617,21 +612,31 @@ static int pci_pm_resume(struct device *dev)
 static int pci_pm_freeze(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct device_driver *drv = dev->driver;
-	int error = 0;
+	struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_suspend(dev, PMSG_FREEZE);
 
-	if (drv && drv->pm && drv->pm->freeze) {
-		error = drv->pm->freeze(dev);
-		suspend_report_result(drv->pm->freeze, error);
+	if (!pm) {
+		pci_pm_default_suspend(pci_dev);
+		return 0;
 	}
 
-	if (!error)
-		pci_pm_default_suspend_generic(pci_dev);
+	pci_dev->state_saved = false;
 
-	return error;
+	if (pm->freeze) {
+		int error;
+
+		error = pm->freeze(dev);
+		suspend_report_result(pm->freeze, error);
+		if (error)
+			return error;
+	}
+
+	if (!pci_dev->state_saved)
+		pci_save_state(pci_dev);
+
+	return 0;
 }
 
 static int pci_pm_freeze_noirq(struct device *dev)
@@ -674,16 +679,18 @@ static int pci_pm_thaw_noirq(struct device *dev)
 static int pci_pm_thaw(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct device_driver *drv = dev->driver;
+	struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int error = 0;
 
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume(dev);
 
-	pci_pm_reenable_device(pci_dev);
-
-	if (drv && drv->pm && drv->pm->thaw)
-		error =  drv->pm->thaw(dev);
+	if (pm) {
+		if (pm->thaw)
+			error = pm->thaw(dev);
+	} else {
+		pci_pm_reenable_device(pci_dev);
+	}
 
 	return error;
 }
@@ -691,19 +698,29 @@ static int pci_pm_thaw(struct device *dev)
 static int pci_pm_poweroff(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct device_driver *drv = dev->driver;
+	struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int error = 0;
 
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_suspend(dev, PMSG_HIBERNATE);
 
-	if (drv && drv->pm && drv->pm->poweroff) {
-		error = drv->pm->poweroff(dev);
-		suspend_report_result(drv->pm->poweroff, error);
+	if (!pm) {
+		pci_pm_default_suspend(pci_dev);
+		goto Fixup;
 	}
 
-	if (!error)
-		pci_pm_default_suspend(pci_dev);
+	pci_dev->state_saved = false;
+
+	if (pm->poweroff) {
+		error = pm->poweroff(dev);
+		suspend_report_result(pm->poweroff, error);
+	}
+
+	if (!pci_dev->state_saved && !pci_is_bridge(pci_dev))
+		pci_prepare_to_sleep(pci_dev);
+
+ Fixup:
+	pci_fixup_device(pci_fixup_suspend, pci_dev);
 
 	return error;
 }
@@ -730,11 +747,11 @@ static int pci_pm_restore_noirq(struct device *dev)
 	struct device_driver *drv = dev->driver;
 	int error = 0;
 
+	pci_pm_default_resume_noirq(pci_dev);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume_early(dev);
 
-	pci_pm_default_resume_noirq(pci_dev);
-
 	if (drv && drv->pm && drv->pm->restore_noirq)
 		error = drv->pm->restore_noirq(dev);
 
@@ -744,16 +761,27 @@ static int pci_pm_restore_noirq(struct device *dev)
 static int pci_pm_restore(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct device_driver *drv = dev->driver;
+	struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 	int error = 0;
 
+	/*
+	 * This is necessary for the hibernation error path in which restore is
+	 * called without restoring the standard config registers of the device.
+	 */
+	if (pci_dev->state_saved)
+		pci_restore_standard_config(pci_dev);
+
 	if (pci_has_legacy_pm_support(pci_dev))
 		return pci_legacy_resume(dev);
 
-	error = pci_pm_default_resume(pci_dev);
+	pci_pm_default_resume(pci_dev);
 
-	if (!error && drv && drv->pm && drv->pm->restore)
-		error = drv->pm->restore(dev);
+	if (pm) {
+		if (pm->restore)
+			error = pm->restore(dev);
+	} else {
+		pci_pm_reenable_device(pci_dev);
+	}
 
 	return error;
 }