Merge branch 'power-refcount' into release

1 files changed, 70 insertions, 97 deletions

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 844c155aeb0..67dedeed144 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -80,18 +80,13 @@ static struct acpi_driver acpi_power_driver = {
                 },
 };
 
-struct acpi_power_reference {
-        struct list_head node;
-        struct acpi_device *device;
-};
-
 struct acpi_power_resource {
         struct acpi_device * device;
         acpi_bus_id name;
         u32 system_level;
         u32 order;
+        unsigned int ref_count;
         struct mutex resource_lock;
-        struct list_head reference;
 };
 
 static struct list_head acpi_power_resource_list;
@@ -184,101 +179,89 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
         return result;
 }
 
-static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
+static int __acpi_power_on(struct acpi_power_resource *resource)
 {
-        int result = 0;
-        int found = 0;
         acpi_status status = AE_OK;
-        struct acpi_power_resource *resource = NULL;
-        struct list_head *node, *next;
-        struct acpi_power_reference *ref;
 
+        status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
+        if (ACPI_FAILURE(status))
+                return -ENODEV;
+
+        /* Update the power resource's _device_ power state */
+        resource->device->power.state = ACPI_STATE_D0;
+
+        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
+                          resource->name));
+
+        return 0;
+}
+
+static int acpi_power_on(acpi_handle handle)
+{
+        int result = 0;
+        struct acpi_power_resource *resource = NULL;
 
         result = acpi_power_get_context(handle, &resource);
         if (result)
                 return result;
 
         mutex_lock(&resource->resource_lock);
-        list_for_each_safe(node, next, &resource->reference) {
-                ref = container_of(node, struct acpi_power_reference, node);
-                if (dev->handle == ref->device->handle) {
-                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
-                                  dev->pnp.bus_id, resource->name));
-                        found = 1;
-                        break;
-                }
-        }
 
-        if (!found) {
-                ref = kmalloc(sizeof (struct acpi_power_reference),
-                    irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
-                if (!ref) {
-                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
-                        mutex_unlock(&resource->resource_lock);
-                        return -ENOMEM;
-                }
-                list_add_tail(&ref->node, &resource->reference);
-                ref->device = dev;
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
-                          dev->pnp.bus_id, resource->name));
+        if (resource->ref_count++) {
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                  "Power resource [%s] already on",
+                                  resource->name));
+        } else {
+                result = __acpi_power_on(resource);
         }
-        mutex_unlock(&resource->resource_lock);
 
-        status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
-        if (ACPI_FAILURE(status))
-                return -ENODEV;
-
-        /* Update the power resource's _device_ power state */
-        resource->device->power.state = ACPI_STATE_D0;
+        mutex_unlock(&resource->resource_lock);
 
-        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
-                          resource->name));
         return 0;
 }
 
-static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
+static int acpi_power_off_device(acpi_handle handle)
 {
         int result = 0;
         acpi_status status = AE_OK;
         struct acpi_power_resource *resource = NULL;
-        struct list_head *node, *next;
-        struct acpi_power_reference *ref;
 
         result = acpi_power_get_context(handle, &resource);
         if (result)
                 return result;
 
         mutex_lock(&resource->resource_lock);
-        list_for_each_safe(node, next, &resource->reference) {
-                ref = container_of(node, struct acpi_power_reference, node);
-                if (dev->handle == ref->device->handle) {
-                        list_del(&ref->node);
-                        kfree(ref);
-                        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
-                            dev->pnp.bus_id, resource->name));
-                        break;
-                }
+
+        if (!resource->ref_count) {
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                  "Power resource [%s] already off",
+                                  resource->name));
+                goto unlock;
         }
 
-        if (!list_empty(&resource->reference)) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
-                    resource->name));
-                mutex_unlock(&resource->resource_lock);
-                return 0;
+        if (--resource->ref_count) {
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                  "Power resource [%s] still in use\n",
+                                  resource->name));
+                goto unlock;
         }
-        mutex_unlock(&resource->resource_lock);
 
         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
-        if (ACPI_FAILURE(status))
-                return -ENODEV;
+        if (ACPI_FAILURE(status)) {
+                result = -ENODEV;
+        } else {
+                /* Update the power resource's _device_ power state */
+                resource->device->power.state = ACPI_STATE_D3;
 
-        /* Update the power resource's _device_ power state */
-        resource->device->power.state = ACPI_STATE_D3;
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                  "Power resource [%s] turned off\n",
+                                  resource->name));
+        }
 
-        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
-                          resource->name));
+ unlock:
+        mutex_unlock(&resource->resource_lock);
 
-        return 0;
+        return result;
 }
 
 /**
@@ -364,7 +347,7 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 
         /* Open power resource */
         for (i = 0; i < dev->wakeup.resources.count; i++) {
-                int ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
+                int ret = acpi_power_on(dev->wakeup.resources.handles[i]);
                 if (ret) {
                         printk(KERN_ERR PREFIX "Transition power state\n");
                         dev->wakeup.flags.valid = 0;
@@ -420,7 +403,7 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
         /* Close power resource */
         for (i = 0; i < dev->wakeup.resources.count; i++) {
                 int ret = acpi_power_off_device(
-                                dev->wakeup.resources.handles[i], dev);
+                                dev->wakeup.resources.handles[i]);
                 if (ret) {
                         printk(KERN_ERR PREFIX "Transition power state\n");
                         dev->wakeup.flags.valid = 0;
@@ -500,7 +483,7 @@ int acpi_power_transition(struct acpi_device *device, int state)
          * (e.g. so the device doesn't lose power while transitioning).
          */
         for (i = 0; i < tl->count; i++) {
-                result = acpi_power_on(tl->handles[i], device);
+                result = acpi_power_on(tl->handles[i]);
                 if (result)
                         goto end;
         }
@@ -513,7 +496,7 @@ int acpi_power_transition(struct acpi_device *device, int state)
          * Then we dereference all power resources used in the current list.
          */
         for (i = 0; i < cl->count; i++) {
-                result = acpi_power_off_device(cl->handles[i], device);
+                result = acpi_power_off_device(cl->handles[i]);
                 if (result)
                         goto end;
         }
@@ -551,7 +534,6 @@ static int acpi_power_add(struct acpi_device *device)
 
         resource->device = device;
         mutex_init(&resource->resource_lock);
-        INIT_LIST_HEAD(&resource->reference);
         strcpy(resource->name, device->pnp.bus_id);
         strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
         strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
@@ -594,22 +576,14 @@ static int acpi_power_add(struct acpi_device *device)
 
 static int acpi_power_remove(struct acpi_device *device, int type)
 {
-        struct acpi_power_resource *resource = NULL;
-        struct list_head *node, *next;
+        struct acpi_power_resource *resource;
 
-
-        if (!device || !acpi_driver_data(device))
+        if (!device)
                 return -EINVAL;
 
         resource = acpi_driver_data(device);
-
-        mutex_lock(&resource->resource_lock);
-        list_for_each_safe(node, next, &resource->reference) {
-                struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
-                list_del(&ref->node);
-                kfree(ref);
-        }
-        mutex_unlock(&resource->resource_lock);
+        if (!resource)
+                return -EINVAL;
 
         kfree(resource);
 
@@ -619,29 +593,28 @@ static int acpi_power_remove(struct acpi_device *device, int type)
 static int acpi_power_resume(struct acpi_device *device)
 {
         int result = 0, state;
-        struct acpi_power_resource *resource = NULL;
-        struct acpi_power_reference *ref;
+        struct acpi_power_resource *resource;
 
-        if (!device || !acpi_driver_data(device))
+        if (!device)
                 return -EINVAL;
 
         resource = acpi_driver_data(device);
+        if (!resource)
+                return -EINVAL;
+
+        mutex_lock(&resource->resource_lock);
 
         result = acpi_power_get_state(device->handle, &state);
         if (result)
-                return result;
+                goto unlock;
 
-        mutex_lock(&resource->resource_lock);
-        if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
-            !list_empty(&resource->reference)) {
-                ref = container_of(resource->reference.next, struct acpi_power_reference, node);
-                mutex_unlock(&resource->resource_lock);
-                result = acpi_power_on(device->handle, ref->device);
-                return result;
-        }
+        if (state == ACPI_POWER_RESOURCE_STATE_OFF && resource->ref_count)
+                result = __acpi_power_on(resource);
 
+ unlock:
         mutex_unlock(&resource->resource_lock);
-        return 0;
+
+        return result;
 }
 
 int __init acpi_power_init(void)