PCI PM: make the PM core more careful with drivers using the new PM framework
[cascardo/linux.git] / drivers / pci / pci-driver.c
index c697f26..93eac14 100644 (file)
@@ -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;
 }