->add_dev() may fail and the error returned from it can be useful for the caller.
For example, if some of the resources aren't ready yet and -EPROBE_DEFER is returned from ->add_dev(), then the owner of 'struct subsys_interface' may want to try probing again at a later point of time. And that requires a proper return value from ->add_dev(). Also, if we hit an error while registering subsys_interface, then we should stop proceeding further and rollback whatever has been done until then. Break part of subsys_interface_unregister() into another routine, which lets us call ->remove_dev() for all devices for which ->add_dev() is already called. Cc: 3.3+ <[email protected]> # 3.3+ Fixes: ca22e56debc5 ("driver-core: implement 'sysdev' functionality for regular devices and buses") Reported-and-tested-by: Pi-Cheng Chen <[email protected]> Signed-off-by: Viresh Kumar <[email protected]> --- drivers/base/bus.c | 55 ++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 35 insertions(+), 20 deletions(-) diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 79bc203f51ef..d92dc109ba51 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -1112,11 +1112,36 @@ void subsys_dev_iter_exit(struct subsys_dev_iter *iter) } EXPORT_SYMBOL_GPL(subsys_dev_iter_exit); +static void __subsys_interface_unregister(struct subsys_interface *sif, + struct device *lastdev) +{ + struct bus_type *subsys = sif->subsys; + struct subsys_dev_iter iter; + struct device *dev; + + mutex_lock(&subsys->p->mutex); + list_del_init(&sif->node); + if (sif->remove_dev) { + subsys_dev_iter_init(&iter, subsys, NULL, NULL); + while ((dev = subsys_dev_iter_next(&iter))) { + if (dev == lastdev) + break; + + sif->remove_dev(dev, sif); + } + subsys_dev_iter_exit(&iter); + } + mutex_unlock(&subsys->p->mutex); + + bus_put(subsys); +} + int subsys_interface_register(struct subsys_interface *sif) { struct bus_type *subsys; struct subsys_dev_iter iter; struct device *dev; + int ret = 0; if (!sif || !sif->subsys) return -ENODEV; @@ -1129,38 +1154,28 @@ int subsys_interface_register(struct subsys_interface *sif) list_add_tail(&sif->node, &subsys->p->interfaces); if (sif->add_dev) { subsys_dev_iter_init(&iter, subsys, NULL, NULL); - while ((dev = subsys_dev_iter_next(&iter))) - sif->add_dev(dev, sif); + while ((dev = subsys_dev_iter_next(&iter))) { + ret = sif->add_dev(dev, sif); + if (ret) + break; + } subsys_dev_iter_exit(&iter); } mutex_unlock(&subsys->p->mutex); - return 0; + if (ret) + __subsys_interface_unregister(sif, dev); + + return ret; } EXPORT_SYMBOL_GPL(subsys_interface_register); void subsys_interface_unregister(struct subsys_interface *sif) { - struct bus_type *subsys; - struct subsys_dev_iter iter; - struct device *dev; - if (!sif || !sif->subsys) return; - subsys = sif->subsys; - - mutex_lock(&subsys->p->mutex); - list_del_init(&sif->node); - if (sif->remove_dev) { - subsys_dev_iter_init(&iter, subsys, NULL, NULL); - while ((dev = subsys_dev_iter_next(&iter))) - sif->remove_dev(dev, sif); - subsys_dev_iter_exit(&iter); - } - mutex_unlock(&subsys->p->mutex); - - bus_put(subsys); + __subsys_interface_unregister(sif, NULL); } EXPORT_SYMBOL_GPL(subsys_interface_unregister); -- 2.4.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
