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authorLen Brown <len.brown@intel.com>2008-10-22 23:57:26 -0400
committerLen Brown <len.brown@intel.com>2008-10-23 00:11:07 -0400
commit057316cc6a5b521b332a1d7ccc871cd60c904c74 (patch)
tree4333e608da237c73ff69b10878025cca96dcb4c8 /drivers/base/core.c
parent3e2dab9a1c2deb03c311eb3f83466009147ed4d3 (diff)
parent2515ddc6db8eb49a79f0fe5e67ff09ac7c81eab4 (diff)
Merge branch 'linus' into test
Conflicts: MAINTAINERS arch/x86/kernel/acpi/boot.c arch/x86/kernel/acpi/sleep.c drivers/acpi/Kconfig drivers/pnp/Makefile drivers/pnp/quirks.c Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/base/core.c')
-rw-r--r--drivers/base/core.c36
1 files changed, 27 insertions, 9 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index d021c98605b..8c2cc2648f5 100644
--- 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)
{