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path: root/drivers/base/core.c
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Diffstat (limited to 'drivers/base/core.c')
-rw-r--r--drivers/base/core.c89
1 files changed, 63 insertions, 26 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index d32a3aefff32..3c4ecb824247 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -365,6 +365,7 @@ struct device_link *device_link_add(struct device *consumer,
link->flags |= DL_FLAG_STATELESS;
goto reorder;
} else {
+ link->flags |= DL_FLAG_STATELESS;
goto out;
}
}
@@ -433,12 +434,16 @@ struct device_link *device_link_add(struct device *consumer,
flags & DL_FLAG_PM_RUNTIME)
pm_runtime_resume(supplier);
+ list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
+ list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
+
if (flags & DL_FLAG_SYNC_STATE_ONLY) {
dev_dbg(consumer,
"Linked as a sync state only consumer to %s\n",
dev_name(supplier));
goto out;
}
+
reorder:
/*
* Move the consumer and all of the devices depending on it to the end
@@ -449,12 +454,9 @@ reorder:
*/
device_reorder_to_tail(consumer, NULL);
- list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
- list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
-
dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
- out:
+out:
device_pm_unlock();
device_links_write_unlock();
@@ -641,9 +643,17 @@ static void device_links_missing_supplier(struct device *dev)
{
struct device_link *link;
- list_for_each_entry(link, &dev->links.suppliers, c_node)
- if (link->status == DL_STATE_CONSUMER_PROBE)
+ list_for_each_entry(link, &dev->links.suppliers, c_node) {
+ if (link->status != DL_STATE_CONSUMER_PROBE)
+ continue;
+
+ if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
+ } else {
+ WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
+ WRITE_ONCE(link->status, DL_STATE_DORMANT);
+ }
+ }
}
/**
@@ -682,11 +692,11 @@ int device_links_check_suppliers(struct device *dev)
device_links_write_lock();
list_for_each_entry(link, &dev->links.suppliers, c_node) {
- if (!(link->flags & DL_FLAG_MANAGED) ||
- link->flags & DL_FLAG_SYNC_STATE_ONLY)
+ if (!(link->flags & DL_FLAG_MANAGED))
continue;
- if (link->status != DL_STATE_AVAILABLE) {
+ if (link->status != DL_STATE_AVAILABLE &&
+ !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
device_links_missing_supplier(dev);
ret = -EPROBE_DEFER;
break;
@@ -829,6 +839,13 @@ static void __device_links_supplier_defer_sync(struct device *sup)
list_add_tail(&sup->links.defer_sync, &deferred_sync);
}
+static void device_link_drop_managed(struct device_link *link)
+{
+ link->flags &= ~DL_FLAG_MANAGED;
+ WRITE_ONCE(link->status, DL_STATE_NONE);
+ kref_put(&link->kref, __device_link_del);
+}
+
/**
* device_links_driver_bound - Update device links after probing its driver.
* @dev: Device to update the links for.
@@ -842,7 +859,7 @@ static void __device_links_supplier_defer_sync(struct device *sup)
*/
void device_links_driver_bound(struct device *dev)
{
- struct device_link *link;
+ struct device_link *link, *ln;
LIST_HEAD(sync_list);
/*
@@ -882,18 +899,35 @@ void device_links_driver_bound(struct device *dev)
else
__device_links_queue_sync_state(dev, &sync_list);
- list_for_each_entry(link, &dev->links.suppliers, c_node) {
+ list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
+ struct device *supplier;
+
if (!(link->flags & DL_FLAG_MANAGED))
continue;
- WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
- WRITE_ONCE(link->status, DL_STATE_ACTIVE);
+ supplier = link->supplier;
+ if (link->flags & DL_FLAG_SYNC_STATE_ONLY) {
+ /*
+ * When DL_FLAG_SYNC_STATE_ONLY is set, it means no
+ * other DL_MANAGED_LINK_FLAGS have been set. So, it's
+ * save to drop the managed link completely.
+ */
+ device_link_drop_managed(link);
+ } else {
+ WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
+ WRITE_ONCE(link->status, DL_STATE_ACTIVE);
+ }
+ /*
+ * This needs to be done even for the deleted
+ * DL_FLAG_SYNC_STATE_ONLY device link in case it was the last
+ * device link that was preventing the supplier from getting a
+ * sync_state() call.
+ */
if (defer_sync_state_count)
- __device_links_supplier_defer_sync(link->supplier);
+ __device_links_supplier_defer_sync(supplier);
else
- __device_links_queue_sync_state(link->supplier,
- &sync_list);
+ __device_links_queue_sync_state(supplier, &sync_list);
}
dev->links.status = DL_DEV_DRIVER_BOUND;
@@ -903,13 +937,6 @@ void device_links_driver_bound(struct device *dev)
device_links_flush_sync_list(&sync_list, dev);
}
-static void device_link_drop_managed(struct device_link *link)
-{
- link->flags &= ~DL_FLAG_MANAGED;
- WRITE_ONCE(link->status, DL_STATE_NONE);
- kref_put(&link->kref, __device_link_del);
-}
-
/**
* __device_links_no_driver - Update links of a device without a driver.
* @dev: Device without a drvier.
@@ -930,11 +957,21 @@ static void __device_links_no_driver(struct device *dev)
if (!(link->flags & DL_FLAG_MANAGED))
continue;
- if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
+ if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
device_link_drop_managed(link);
- else if (link->status == DL_STATE_CONSUMER_PROBE ||
- link->status == DL_STATE_ACTIVE)
+ continue;
+ }
+
+ if (link->status != DL_STATE_CONSUMER_PROBE &&
+ link->status != DL_STATE_ACTIVE)
+ continue;
+
+ if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
+ } else {
+ WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
+ WRITE_ONCE(link->status, DL_STATE_DORMANT);
+ }
}
dev->links.status = DL_DEV_NO_DRIVER;