diff options
author | Cornelia Huck <cornelia.huck@de.ibm.com> | 2008-09-03 12:26:40 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-10-16 12:24:48 -0400 |
commit | 5739411acbaa63a6c22c91e340fdcdbcc7d82a51 (patch) | |
tree | 1f54912f36211076a341067395599ec449bc1ae5 /drivers/base/core.c | |
parent | 9cf899d12583082c77a0fcc758f3179b440518ee (diff) |
Driver core: Clarify device cleanup.
Make the comments on how to use device_initialize(), device_add()
and device_register() a bit clearer - in particular, explicitly
note that put_device() must be used once we tried to add the device
to the hierarchy.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/base/core.c')
-rw-r--r-- | drivers/base/core.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index b98cb1416a2d..aac91e89d6af 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c | |||
@@ -523,11 +523,16 @@ static void klist_children_put(struct klist_node *n) | |||
523 | * device_initialize - init device structure. | 523 | * device_initialize - init device structure. |
524 | * @dev: device. | 524 | * @dev: device. |
525 | * | 525 | * |
526 | * This prepares the device for use by other layers, | 526 | * This prepares the device for use by other layers by initializing |
527 | * including adding it to the device hierarchy. | 527 | * its fields. |
528 | * It is the first half of device_register(), if called by | 528 | * It is the first half of device_register(), if called by |
529 | * that, though it can also be called separately, so one | 529 | * that function, though it can also be called separately, so one |
530 | * may use @dev's fields (e.g. the refcount). | 530 | * may use @dev's fields. In particular, get_device()/put_device() |
531 | * may be used for reference counting of @dev after calling this | ||
532 | * function. | ||
533 | * | ||
534 | * NOTE: Use put_device() to give up your reference instead of freeing | ||
535 | * @dev directly once you have called this function. | ||
531 | */ | 536 | */ |
532 | void device_initialize(struct device *dev) | 537 | void device_initialize(struct device *dev) |
533 | { | 538 | { |
@@ -835,9 +840,13 @@ static void device_remove_sys_dev_entry(struct device *dev) | |||
835 | * This is part 2 of device_register(), though may be called | 840 | * This is part 2 of device_register(), though may be called |
836 | * separately _iff_ device_initialize() has been called separately. | 841 | * separately _iff_ device_initialize() has been called separately. |
837 | * | 842 | * |
838 | * This adds it to the kobject hierarchy via kobject_add(), adds it | 843 | * This adds @dev to the kobject hierarchy via kobject_add(), adds it |
839 | * to the global and sibling lists for the device, then | 844 | * to the global and sibling lists for the device, then |
840 | * adds it to the other relevant subsystems of the driver model. | 845 | * adds it to the other relevant subsystems of the driver model. |
846 | * | ||
847 | * NOTE: _Never_ directly free @dev after calling this function, even | ||
848 | * if it returned an error! Always use put_device() to give up your | ||
849 | * reference instead. | ||
841 | */ | 850 | */ |
842 | int device_add(struct device *dev) | 851 | int device_add(struct device *dev) |
843 | { | 852 | { |
@@ -965,6 +974,10 @@ done: | |||
965 | * I.e. you should only call the two helpers separately if | 974 | * I.e. you should only call the two helpers separately if |
966 | * have a clearly defined need to use and refcount the device | 975 | * have a clearly defined need to use and refcount the device |
967 | * before it is added to the hierarchy. | 976 | * before it is added to the hierarchy. |
977 | * | ||
978 | * NOTE: _Never_ directly free @dev after calling this function, even | ||
979 | * if it returned an error! Always use put_device() to give up the | ||
980 | * reference initialized in this function instead. | ||
968 | */ | 981 | */ |
969 | int device_register(struct device *dev) | 982 | int device_register(struct device *dev) |
970 | { | 983 | { |