Messages in this thread | ![/](/images/icornerl.gif) | | From | "Rafael J. Wysocki" <> | Date | Tue, 10 Jan 2023 13:52:24 +0100 | Subject | Re: [PATCH 1/2] driver core: bus.h: document bus notifiers better |
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On Tue, Jan 10, 2023 at 1:43 PM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > 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@kernel.org> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > 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,
I'm wondering why the values are in hex (the 0x prefix doesn't matter for these numbers AFAICS) and what the initial zeros are for (AFAICS they don't matter either).
> +}; > > extern struct kset *bus_get_kset(struct bus_type *bus); > > --
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