diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 4a67cc0c8b37..74dda4f697f9 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -632,6 +632,11 @@ static void klist_children_put(struct klist_node *n) * may be used for reference counting of @dev after calling this * function. * + * All fields in @dev must be initialized by the caller to 0, except + * for those explicitly set to some other value. The simplest + * approach is to use kzalloc() to allocate the structure containing + * @dev. + * * NOTE: Use put_device() to give up your reference instead of freeing * @dev directly once you have called this function. */ @@ -930,6 +935,13 @@ int device_private_init(struct device *dev) * to the global and sibling lists for the device, then * adds it to the other relevant subsystems of the driver model. * + * Do not call this routine or device_register() more than once for + * any device structure. The driver model core is not designed to work + * with devices that get unregistered and then spring back to life. + * (Among other things, it's very hard to guarantee that all references + * to the previous incarnation of @dev have been dropped.) Allocate + * and register a fresh new struct device instead. + * * 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. @@ -1022,7 +1034,7 @@ int device_add(struct device *dev) device_pm_add(dev); /* Notify clients of device addition. This call must come - * after dpm_sysf_add() and before kobject_uevent(). + * after dpm_sysfs_add() and before kobject_uevent(). */ if (dev->bus) blocking_notifier_call_chain(&dev->bus->p->bus_notifier, @@ -1090,6 +1102,9 @@ name_error: * have a clearly defined need to use and refcount the device * before it is added to the hierarchy. * + * For more information, see the kerneldoc for device_initialize() + * and device_add(). + * * 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. |