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;
 }