Merge tag 'pm-for-3.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael J. Wysocki:
 "Three ACPI device power management fixes related to checking and
  setting device power states."

* tag 'pm-for-3.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / PM: Use KERN_DEBUG when no power resources are found
  ACPI / PM: Fix resource_lock dead lock in acpi_power_on_device
  ACPI / PM: Infer parent power state from child if unknown, v2

2 files changed, 34 insertions, 12 deletions

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 9628652e080c..e0596954290b 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -237,6 +237,16 @@ static int __acpi_bus_get_power(struct acpi_device *device, int *state)
         } else if (result == ACPI_STATE_D3_HOT) {
                 result = ACPI_STATE_D3;
         }
+
+        /*
+         * If we were unsure about the device parent's power state up to this
+         * point, the fact that the device is in D0 implies that the parent has
+         * to be in D0 too.
+         */
+        if (device->parent && device->parent->power.state == ACPI_STATE_UNKNOWN
+            && result == ACPI_STATE_D0)
+                device->parent->power.state = ACPI_STATE_D0;
+
         *state = result;
 
  out:
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index fc1803414629..40e38a06ba85 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -107,6 +107,7 @@ struct acpi_power_resource {
 
         /* List of devices relying on this power resource */
         struct acpi_power_resource_device *devices;
+        struct mutex devices_lock;
 };
 
 static struct list_head acpi_power_resource_list;
@@ -225,7 +226,6 @@ static void acpi_power_on_device(struct acpi_power_managed_device *device)
 
 static int __acpi_power_on(struct acpi_power_resource *resource)
 {
-        struct acpi_power_resource_device *device_list = resource->devices;
         acpi_status status = AE_OK;
 
         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
@@ -238,19 +238,15 @@ static int __acpi_power_on(struct acpi_power_resource *resource)
         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
                           resource->name));
 
-        while (device_list) {
-                acpi_power_on_device(device_list->device);
-
-                device_list = device_list->next;
-        }
-
         return 0;
 }
 
 static int acpi_power_on(acpi_handle handle)
 {
         int result = 0;
+        bool resume_device = false;
         struct acpi_power_resource *resource = NULL;
+        struct acpi_power_resource_device *device_list;
 
         result = acpi_power_get_context(handle, &resource);
         if (result)
@@ -266,10 +262,25 @@ static int acpi_power_on(acpi_handle handle)
                 result = __acpi_power_on(resource);
                 if (result)
                         resource->ref_count--;
+                else
+                        resume_device = true;
         }
 
         mutex_unlock(&resource->resource_lock);
 
+        if (!resume_device)
+                return result;
+
+        mutex_lock(&resource->devices_lock);
+
+        device_list = resource->devices;
+        while (device_list) {
+                acpi_power_on_device(device_list->device);
+                device_list = device_list->next;
+        }
+
+        mutex_unlock(&resource->devices_lock);
+
         return result;
 }
 
@@ -355,7 +366,7 @@ static void __acpi_power_resource_unregister_device(struct device *dev,
         if (acpi_power_get_context(res_handle, &resource))
                 return;
 
-        mutex_lock(&resource->resource_lock);
+        mutex_lock(&resource->devices_lock);
         prev = NULL;
         curr = resource->devices;
         while (curr) {
@@ -372,7 +383,7 @@ static void __acpi_power_resource_unregister_device(struct device *dev,
                 prev = curr;
                 curr = curr->next;
         }
-        mutex_unlock(&resource->resource_lock);
+        mutex_unlock(&resource->devices_lock);
 }
 
 /* Unlink dev from all power resources in _PR0 */
@@ -414,10 +425,10 @@ static int __acpi_power_resource_register_device(
 
         power_resource_device->device = powered_device;
 
-        mutex_lock(&resource->resource_lock);
+        mutex_lock(&resource->devices_lock);
         power_resource_device->next = resource->devices;
         resource->devices = power_resource_device;
-        mutex_unlock(&resource->resource_lock);
+        mutex_unlock(&resource->devices_lock);
 
         return 0;
 }
@@ -462,7 +473,7 @@ int acpi_power_resource_register_device(struct device *dev, acpi_handle handle)
         return ret;
 
 no_power_resource:
-        printk(KERN_WARNING PREFIX "Invalid Power Resource to register!");
+        printk(KERN_DEBUG PREFIX "Invalid Power Resource to register!");
         return -ENODEV;
 }
 EXPORT_SYMBOL_GPL(acpi_power_resource_register_device);
@@ -721,6 +732,7 @@ static int acpi_power_add(struct acpi_device *device)
 
         resource->device = device;
         mutex_init(&resource->resource_lock);
+        mutex_init(&resource->devices_lock);
         strcpy(resource->name, device->pnp.bus_id);
         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);