PCI PM: Restore standard config registers of all devices early

[deliverable/linux.git] / drivers / pci / pci-driver.c

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index c697f268085698bf886e7b3a358f5343b3ce5c71..9de07b75b993b0e81346cd516c2021849d50901e 100644 (file)
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -355,17 +355,27 @@ static int pci_legacy_suspend(struct device *dev, pm_message_t state)
        int i = 0;
 
        if (drv && drv->suspend) {
+               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 (WARN_ON_ONCE(pci_dev->current_state != PCI_D0))
+                       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;
@@ -386,81 +396,34 @@ 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_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))
@@ -575,11 +538,11 @@ 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);
 
@@ -730,11 +693,11 @@ 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);