diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 3c5ff17f578f..876c62b12462 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -152,6 +152,14 @@ static int device_reorder_to_tail(struct device *dev, void *not_used) * @supplier: Supplier end of the link. * @flags: Link flags. * + * The caller is responsible for the proper synchronization of the link creation + * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the + * runtime PM framework to take the link into account. Second, if the + * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will + * be forced into the active metastate and reference-counted upon the creation + * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be + * ignored. + * * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically * when the consumer device driver unbinds from it. The combination of both * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL @@ -193,10 +201,19 @@ struct device_link *device_link_add(struct device *consumer, if (link->consumer == consumer) goto out; - link = kmalloc(sizeof(*link), GFP_KERNEL); + link = kzalloc(sizeof(*link), GFP_KERNEL); if (!link) goto out; + if ((flags & DL_FLAG_PM_RUNTIME) && (flags & DL_FLAG_RPM_ACTIVE)) { + if (pm_runtime_get_sync(supplier) < 0) { + pm_runtime_put_noidle(supplier); + kfree(link); + link = NULL; + goto out; + } + link->rpm_active = true; + } get_device(supplier); link->supplier = supplier; INIT_LIST_HEAD(&link->s_node); @@ -213,6 +230,14 @@ struct device_link *device_link_add(struct device *consumer, case DL_DEV_DRIVER_BOUND: switch (consumer->links.status) { case DL_DEV_PROBING: + /* + * Balance the decrementation of the supplier's + * runtime PM usage counter after consumer probe + * in driver_probe_device(). + */ + if (flags & DL_FLAG_PM_RUNTIME) + pm_runtime_get_sync(supplier); + link->status = DL_STATE_CONSUMER_PROBE; break; case DL_DEV_DRIVER_BOUND: |