[PATCH 1/2] driver core: bus.h: document bus notifiers better

From: Greg Kroah-Hartman
Date: Tue Jan 10 2023 - 07:43:25 EST


The bus notifier values are not documented all that well, so clean this
up and make a real enumerated type for them and document them much
better.

Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/device/bus.h | 43 +++++++++++++++++++++++++-------------
1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h
index d529f644e92b..1e1a593348bc 100644
--- a/include/linux/device/bus.h
+++ b/include/linux/device/bus.h
@@ -257,21 +257,36 @@ extern int bus_register_notifier(struct bus_type *bus,
extern int bus_unregister_notifier(struct bus_type *bus,
struct notifier_block *nb);

-/* All 4 notifers below get called with the target struct device *
- * as an argument. Note that those functions are likely to be called
- * with the device lock held in the core, so be careful.
+/**
+ * enum bus_notifier_event: Bus Notifier events that have happened
+ *
+ * These are the value passed to a bus notifier when a specific event happens.
+ *
+ * Note that bus notifiers are likely to be called with the device lock already
+ * held by the driver core, so be careful in any notifier callback as to what
+ * you do with the device structure.
+ *
+ * All bus notifiers are called with the target struct device * as an argument.
+ *
+ * BUS_NOTIFY_ADD_DEVICE: device is added to this bus
+ * BUS_NOTIFY_DEL_DEVICE: device is about to be removed from this bus
+ * BUS_NOTIFY_REMOVED_DEVICE: device is successfully removed from this bus
+ * BUS_NOTIFY_BIND_DRIVER: a driver is about to be bound to this device on this bus
+ * BUS_NOTIFY_BOUND_DRIVER: a driver is successfully bound to this device on this bus
+ * BUS_NOTIFY_UNBIND_DRIVER: a driver is about to be unbound from this device on this bus
+ * BUS_NOTIFY_UNBOUND_DRIVER: a driver is successfully unbound from this device on this bus
+ * BUS_NOTIFY_DRIVER_NOT_BOUND: a driver failed to be bound to this device on this bus
*/
-#define BUS_NOTIFY_ADD_DEVICE 0x00000001 /* device added */
-#define BUS_NOTIFY_DEL_DEVICE 0x00000002 /* device to be removed */
-#define BUS_NOTIFY_REMOVED_DEVICE 0x00000003 /* device removed */
-#define BUS_NOTIFY_BIND_DRIVER 0x00000004 /* driver about to be
- bound */
-#define BUS_NOTIFY_BOUND_DRIVER 0x00000005 /* driver bound to device */
-#define BUS_NOTIFY_UNBIND_DRIVER 0x00000006 /* driver about to be
- unbound */
-#define BUS_NOTIFY_UNBOUND_DRIVER 0x00000007 /* driver is unbound
- from the device */
-#define BUS_NOTIFY_DRIVER_NOT_BOUND 0x00000008 /* driver fails to be bound */
+enum bus_notifier_event {
+ BUS_NOTIFY_ADD_DEVICE = 0x00000001,
+ BUS_NOTIFY_DEL_DEVICE = 0x00000002,
+ BUS_NOTIFY_REMOVED_DEVICE = 0x00000003,
+ BUS_NOTIFY_BIND_DRIVER = 0x00000004,
+ BUS_NOTIFY_BOUND_DRIVER = 0x00000005,
+ BUS_NOTIFY_UNBIND_DRIVER = 0x00000006,
+ BUS_NOTIFY_UNBOUND_DRIVER = 0x00000007,
+ BUS_NOTIFY_DRIVER_NOT_BOUND = 0x00000008,
+};

extern struct kset *bus_get_kset(struct bus_type *bus);

--
2.39.0