3 files changed, 74 insertions, 38 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index bfaa77d88537..750ee79c178f 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -316,21 +316,10 @@ static void pci_device_shutdown(struct device *dev)
 
 /*
  * Default "suspend" method for devices that have no driver provided suspend,
- * or not even a driver at all (first part).
- */
-static void pci_default_pm_suspend_early(struct pci_dev *pci_dev)
-{
-        /* If device is enabled at this point, disable it */
-        pci_disable_enabled_device(pci_dev);
-}
-
-/*
- * Default "suspend" method for devices that have no driver provided suspend,
  * or not even a driver at all (second part).
  */
 static void pci_default_pm_suspend_late(struct pci_dev *pci_dev)
 {
-        pci_save_state(pci_dev);
         /*
          * mark its power state as "unknown", since we don't know if
          * e.g. the BIOS will change its device state when we suspend.
@@ -341,16 +330,6 @@ static void pci_default_pm_suspend_late(struct pci_dev *pci_dev)
 
 /*
  * Default "resume" method for devices that have no driver provided resume,
- * or not even a driver at all (first part).
- */
-static void pci_default_pm_resume_early(struct pci_dev *pci_dev)
-{
-        /* restore the PCI config space */
-        pci_restore_state(pci_dev);
-}
-
-/*
- * Default "resume" method for devices that have no driver provided resume,
  * or not even a driver at all (second part).
  */
 static int pci_default_pm_resume_late(struct pci_dev *pci_dev)
@@ -379,9 +358,10 @@ static int pci_legacy_suspend(struct device *dev, pm_message_t state)
                 i = drv->suspend(pci_dev, state);
                 suspend_report_result(drv->suspend, i);
         } else {
+                pci_save_state(pci_dev);
                 /*
-                 * For compatibility with existing code with legacy PM support
-                 * don't call pci_default_pm_suspend_early() here.
+                 * This is for compatibility with existing code with legacy PM
+                 * support.
                  */
                 pci_default_pm_suspend_late(pci_dev);
         }
@@ -410,7 +390,8 @@ static int pci_legacy_resume(struct device *dev)
         if (drv && drv->resume) {
                 error = drv->resume(pci_dev);
         } else {
-                pci_default_pm_resume_early(pci_dev);
+                /* restore the PCI config space */
+                pci_restore_state(pci_dev);
                 error = pci_default_pm_resume_late(pci_dev);
         }
         return error;
@@ -429,22 +410,72 @@ static int pci_legacy_resume_early(struct device *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);
+}
+
 static int 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_default_pm_resume_late(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_default_pm_suspend_early(pci_dev);
+        pci_pm_default_suspend_generic(pci_dev);
 
         if (!pci_is_bridge(pci_dev))
                 pci_prepare_to_sleep(pci_dev);
@@ -529,12 +560,13 @@ static int pci_pm_resume(struct device *dev)
         struct device_driver *drv = dev->driver;
         int error = 0;
 
-        pci_fixup_device(pci_fixup_resume, pci_dev);
-
         if (drv && drv->pm) {
+                pci_fixup_device(pci_fixup_resume, pci_dev);
+
                 if (drv->pm->resume)
                         error = drv->pm->resume(dev);
         } else if (pci_has_legacy_pm_support(pci_dev)) {
+                pci_fixup_device(pci_fixup_resume, pci_dev);
                 error = pci_legacy_resume(dev);
         } else {
                 error = pci_pm_default_resume(pci_dev);
@@ -549,15 +581,16 @@ static int pci_pm_resume_noirq(struct device *dev)
         struct device_driver *drv = dev->driver;
         int error = 0;
 
-        pci_fixup_device(pci_fixup_resume_early, to_pci_dev(dev));
-
         if (drv && drv->pm) {
+                pci_fixup_device(pci_fixup_resume_early, pci_dev);
+
                 if (drv->pm->resume_noirq)
                         error = drv->pm->resume_noirq(dev);
         } else if (pci_has_legacy_pm_support(pci_dev)) {
+                pci_fixup_device(pci_fixup_resume_early, pci_dev);
                 error = pci_legacy_resume_early(dev);
         } else {
-                pci_default_pm_resume_early(pci_dev);
+                pci_pm_default_resume_noirq(pci_dev);
         }
 
         return error;
@@ -589,7 +622,7 @@ static int pci_pm_freeze(struct device *dev)
                 error = pci_legacy_suspend(dev, PMSG_FREEZE);
                 pci_fixup_device(pci_fixup_suspend, pci_dev);
         } else {
-                pci_default_pm_suspend_early(pci_dev);
+                pci_pm_default_suspend_generic(pci_dev);
         }
 
         return error;
@@ -647,7 +680,7 @@ static int pci_pm_thaw_noirq(struct device *dev)
                 pci_fixup_device(pci_fixup_resume_early, to_pci_dev(dev));
                 error = pci_legacy_resume_early(dev);
         } else {
-                pci_default_pm_resume_early(pci_dev);
+                pci_update_current_state(pci_dev, PCI_D0);
         }
 
         return error;
@@ -698,12 +731,13 @@ static int pci_pm_restore(struct device *dev)
         struct device_driver *drv = dev->driver;
         int error = 0;
 
-        pci_fixup_device(pci_fixup_resume, pci_dev);
-
         if (drv && drv->pm) {
+                pci_fixup_device(pci_fixup_resume, pci_dev);
+
                 if (drv->pm->restore)
                         error = drv->pm->restore(dev);
         } else if (pci_has_legacy_pm_support(pci_dev)) {
+                pci_fixup_device(pci_fixup_resume, pci_dev);
                 error = pci_legacy_resume(dev);
         } else {
                 error = pci_pm_default_resume(pci_dev);
@@ -718,15 +752,16 @@ static int pci_pm_restore_noirq(struct device *dev)
         struct device_driver *drv = dev->driver;
         int error = 0;
 
-        pci_fixup_device(pci_fixup_resume_early, pci_dev);
-
         if (drv && drv->pm) {
+                pci_fixup_device(pci_fixup_resume_early, pci_dev);
+
                 if (drv->pm->restore_noirq)
                         error = drv->pm->restore_noirq(dev);
         } else if (pci_has_legacy_pm_support(pci_dev)) {
+                pci_fixup_device(pci_fixup_resume_early, pci_dev);
                 error = pci_legacy_resume_early(dev);
         } else {
-                pci_default_pm_resume_early(pci_dev);
+                pci_pm_default_resume_noirq(pci_dev);
         }
 
         return error;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6e309c8b47df..e491fdedf705 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -527,7 +527,7 @@ pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
  * @dev: PCI device to handle.
  * @state: State to cache in case the device doesn't have the PM capability
  */
-static void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
+void pci_update_current_state(struct pci_dev *dev, pci_power_t state)
 {
         if (dev->pm_cap) {
                 u16 pmcsr;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 881dc15f8efd..1351bb4addde 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -44,6 +44,7 @@ struct pci_platform_pm_ops {
 };
 
 extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops);
+extern void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
 extern void pci_disable_enabled_device(struct pci_dev *dev);
 extern void pci_pm_init(struct pci_dev *dev);
 extern void platform_pci_wakeup_init(struct pci_dev *dev);