Merge branch 'linus' into core/urgent

[linux-2.6-omap-h63xx.git] / drivers / base / core.c

diff --git a/drivers/base/core.c b/drivers/base/core.c
index d021c98605b3a1fe7e7dcd5f61e9e456b2a16aae..8c2cc2648f5a5c0ec330df4991f75b6be07131ae 100644 (file)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -523,11 +523,16 @@ static void klist_children_put(struct klist_node *n)
  * device_initialize - init device structure.
  * @dev: device.
  *
- * This prepares the device for use by other layers,
- * including adding it to the device hierarchy.
+ * This prepares the device for use by other layers by initializing
+ * its fields.
  * It is the first half of device_register(), if called by
- * that, though it can also be called separately, so one
- * may use @dev's fields (e.g. the refcount).
+ * that function, though it can also be called separately, so one
+ * may use @dev's fields. In particular, get_device()/put_device()
+ * may be used for reference counting of @dev after calling this
+ * function.
+ *
+ * NOTE: Use put_device() to give up your reference instead of freeing
+ * @dev directly once you have called this function.
  */
 void device_initialize(struct device *dev)
 {
@@ -536,7 +541,6 @@ void device_initialize(struct device *dev)
        klist_init(&dev->klist_children, klist_children_get,
                   klist_children_put);
        INIT_LIST_HEAD(&dev->dma_pools);
-       INIT_LIST_HEAD(&dev->node);
        init_MUTEX(&dev->sem);
        spin_lock_init(&dev->devres_lock);
        INIT_LIST_HEAD(&dev->devres_head);
@@ -836,9 +840,13 @@ static void device_remove_sys_dev_entry(struct device *dev)
  * This is part 2 of device_register(), though may be called
  * separately _iff_ device_initialize() has been called separately.
  *
- * This adds it to the kobject hierarchy via kobject_add(), adds it
+ * This adds @dev to the kobject hierarchy via kobject_add(), adds it
  * to the global and sibling lists for the device, then
  * adds it to the other relevant subsystems of the driver model.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up your
+ * reference instead.
  */
 int device_add(struct device *dev)
 {
@@ -916,7 +924,8 @@ int device_add(struct device *dev)
        if (dev->class) {
                mutex_lock(&dev->class->p->class_mutex);
                /* tie the class to the device */
-               list_add_tail(&dev->node, &dev->class->p->class_devices);
+               klist_add_tail(&dev->knode_class,
+                              &dev->class->p->class_devices);
 
                /* notify any interfaces that the device is here */
                list_for_each_entry(class_intf,
@@ -965,6 +974,10 @@ done:
  * I.e. you should only call the two helpers separately if
  * have a clearly defined need to use and refcount the device
  * before it is added to the hierarchy.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use put_device() to give up the
+ * reference initialized in this function instead.
  */
 int device_register(struct device *dev)
 {
@@ -1032,7 +1045,7 @@ void device_del(struct device *dev)
                        if (class_intf->remove_dev)
                                class_intf->remove_dev(dev, class_intf);
                /* remove the device from the class list */
-               list_del_init(&dev->node);
+               klist_del(&dev->knode_class);
                mutex_unlock(&dev->class->p->class_mutex);
        }
        device_remove_file(dev, &uevent_attr);
@@ -1243,7 +1256,7 @@ struct device *device_create_vargs(struct class *class, struct device *parent,
        return dev;
 
 error:
-       kfree(dev);
+       put_device(dev);
        return ERR_PTR(retval);
 }
 EXPORT_SYMBOL_GPL(device_create_vargs);
@@ -1314,6 +1327,11 @@ EXPORT_SYMBOL_GPL(device_destroy);
  * device_rename - renames a device
  * @dev: the pointer to the struct device to be renamed
  * @new_name: the new name of the device
+ *
+ * It is the responsibility of the caller to provide mutual
+ * exclusion between two different calls of device_rename
+ * on the same device to ensure that new_name is valid and
+ * won't conflict with other devices.
  */
 int device_rename(struct device *dev, char *new_name)
 {