diff options
-rw-r--r-- | drivers/base/core.c | 25 | ||||
-rw-r--r-- | include/linux/device.h | 2 |
2 files changed, 19 insertions, 8 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 5847364f25d9..b610816eb887 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -196,8 +196,10 @@ struct device_link *device_link_add(struct device *consumer, } list_for_each_entry(link, &supplier->links.consumers, s_node) - if (link->consumer == consumer) + if (link->consumer == consumer) { + kref_get(&link->kref); goto out; + } link = kzalloc(sizeof(*link), GFP_KERNEL); if (!link) @@ -222,6 +224,7 @@ struct device_link *device_link_add(struct device *consumer, link->consumer = consumer; INIT_LIST_HEAD(&link->c_node); link->flags = flags; + kref_init(&link->kref); /* Determine the initial link state. */ if (flags & DL_FLAG_STATELESS) { @@ -292,8 +295,10 @@ static void __device_link_free_srcu(struct rcu_head *rhead) device_link_free(container_of(rhead, struct device_link, rcu_head)); } -static void __device_link_del(struct device_link *link) +static void __device_link_del(struct kref *kref) { + struct device_link *link = container_of(kref, struct device_link, kref); + dev_info(link->consumer, "Dropping the link to %s\n", dev_name(link->supplier)); @@ -305,8 +310,10 @@ static void __device_link_del(struct device_link *link) call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu); } #else /* !CONFIG_SRCU */ -static void __device_link_del(struct device_link *link) +static void __device_link_del(struct kref *kref) { + struct device_link *link = container_of(kref, struct device_link, kref); + dev_info(link->consumer, "Dropping the link to %s\n", dev_name(link->supplier)); @@ -324,13 +331,15 @@ static void __device_link_del(struct device_link *link) * @link: Device link to delete. * * The caller must ensure proper synchronization of this function with runtime - * PM. + * PM. If the link was added multiple times, it needs to be deleted as often. + * Care is required for hotplugged devices: Their links are purged on removal + * and calling device_link_del() is then no longer allowed. */ void device_link_del(struct device_link *link) { device_links_write_lock(); device_pm_lock(); - __device_link_del(link); + kref_put(&link->kref, __device_link_del); device_pm_unlock(); device_links_write_unlock(); } @@ -444,7 +453,7 @@ static void __device_links_no_driver(struct device *dev) continue; if (link->flags & DL_FLAG_AUTOREMOVE) - __device_link_del(link); + kref_put(&link->kref, __device_link_del); else if (link->status != DL_STATE_SUPPLIER_UNBIND) WRITE_ONCE(link->status, DL_STATE_AVAILABLE); } @@ -597,13 +606,13 @@ static void device_links_purge(struct device *dev) list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) { WARN_ON(link->status == DL_STATE_ACTIVE); - __device_link_del(link); + __device_link_del(&link->kref); } list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) { WARN_ON(link->status != DL_STATE_DORMANT && link->status != DL_STATE_NONE); - __device_link_del(link); + __device_link_del(&link->kref); } device_links_write_unlock(); diff --git a/include/linux/device.h b/include/linux/device.h index b093405ed525..abf952c82c6d 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -769,6 +769,7 @@ enum device_link_state { * @status: The state of the link (with respect to the presence of drivers). * @flags: Link flags. * @rpm_active: Whether or not the consumer device is runtime-PM-active. + * @kref: Count repeated addition of the same link. * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks. */ struct device_link { @@ -779,6 +780,7 @@ struct device_link { enum device_link_state status; u32 flags; bool rpm_active; + struct kref kref; #ifdef CONFIG_SRCU struct rcu_head rcu_head; #endif |