return NULL;
}
+/* Find the sub-device notifier registered by a sub-device driver. */
+static struct v4l2_async_notifier *v4l2_async_find_subdev_notifier(
+ struct v4l2_subdev *sd)
+{
+ struct v4l2_async_notifier *n;
+
+ list_for_each_entry(n, ¬ifier_list, list)
+ if (n->sd == sd)
+ return n;
+
+ return NULL;
+}
+
+/* Get v4l2_device related to the notifier if one can be found. */
+static struct v4l2_device *v4l2_async_notifier_find_v4l2_dev(
+ struct v4l2_async_notifier *notifier)
+{
+ while (notifier->parent)
+ notifier = notifier->parent;
+
+ return notifier->v4l2_dev;
+}
+
+/*
+ * Return true if all child sub-device notifiers are complete, false otherwise.
+ */
+static bool v4l2_async_notifier_can_complete(
+ struct v4l2_async_notifier *notifier)
+{
+ struct v4l2_subdev *sd;
+
+ if (!list_empty(¬ifier->waiting))
+ return false;
+
+ list_for_each_entry(sd, ¬ifier->done, async_list) {
+ struct v4l2_async_notifier *subdev_notifier =
+ v4l2_async_find_subdev_notifier(sd);
+
+ if (subdev_notifier &&
+ !v4l2_async_notifier_can_complete(subdev_notifier))
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * Complete the master notifier if possible. This is done when all async
+ * sub-devices have been bound; v4l2_device is also available then.
+ */
+static int v4l2_async_notifier_try_complete(
+ struct v4l2_async_notifier *notifier)
+{
+ /* Quick check whether there are still more sub-devices here. */
+ if (!list_empty(¬ifier->waiting))
+ return 0;
+
+ /* Check the entire notifier tree; find the root notifier first. */
+ while (notifier->parent)
+ notifier = notifier->parent;
+
+ /* This is root if it has v4l2_dev. */
+ if (!notifier->v4l2_dev)
+ return 0;
+
+ /* Is everything ready? */
+ if (!v4l2_async_notifier_can_complete(notifier))
+ return 0;
+
+ return v4l2_async_notifier_call_complete(notifier);
+}
+
+static int v4l2_async_notifier_try_all_subdevs(
+ struct v4l2_async_notifier *notifier);
+
static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
struct v4l2_device *v4l2_dev,
struct v4l2_subdev *sd,
struct v4l2_async_subdev *asd)
{
+ struct v4l2_async_notifier *subdev_notifier;
int ret;
ret = v4l2_device_register_subdev(v4l2_dev, sd);
/* Move from the global subdevice list to notifier's done */
list_move(&sd->async_list, ¬ifier->done);
- return 0;
+ /*
+ * See if the sub-device has a notifier. If not, return here.
+ */
+ subdev_notifier = v4l2_async_find_subdev_notifier(sd);
+ if (!subdev_notifier || subdev_notifier->parent)
+ return 0;
+
+ /*
+ * Proceed with checking for the sub-device notifier's async
+ * sub-devices, and return the result. The error will be handled by the
+ * caller.
+ */
+ subdev_notifier->parent = notifier;
+
+ return v4l2_async_notifier_try_all_subdevs(subdev_notifier);
}
/* Test all async sub-devices in a notifier for a match. */
static int v4l2_async_notifier_try_all_subdevs(
struct v4l2_async_notifier *notifier)
{
- struct v4l2_device *v4l2_dev = notifier->v4l2_dev;
- struct v4l2_subdev *sd, *tmp;
+ struct v4l2_device *v4l2_dev =
+ v4l2_async_notifier_find_v4l2_dev(notifier);
+ struct v4l2_subdev *sd;
+
+ if (!v4l2_dev)
+ return 0;
- list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
+again:
+ list_for_each_entry(sd, &subdev_list, async_list) {
struct v4l2_async_subdev *asd;
int ret;
ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
if (ret < 0)
return ret;
+
+ /*
+ * v4l2_async_match_notify() may lead to registering a
+ * new notifier and thus changing the async subdevs
+ * list. In order to proceed safely from here, restart
+ * parsing the list from the beginning.
+ */
+ goto again;
}
return 0;
sd->asd = NULL;
}
+/* Unbind all sub-devices in the notifier tree. */
static void v4l2_async_notifier_unbind_all_subdevs(
struct v4l2_async_notifier *notifier)
{
struct v4l2_subdev *sd, *tmp;
list_for_each_entry_safe(sd, tmp, ¬ifier->done, async_list) {
+ struct v4l2_async_notifier *subdev_notifier =
+ v4l2_async_find_subdev_notifier(sd);
+
+ if (subdev_notifier)
+ v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
+
v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
v4l2_async_cleanup(sd);
list_move(&sd->async_list, &subdev_list);
}
+
+ notifier->parent = NULL;
}
static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
INIT_LIST_HEAD(¬ifier->waiting);
INIT_LIST_HEAD(¬ifier->done);
- if (!notifier->num_subdevs) {
- int ret;
-
- ret = v4l2_async_notifier_call_complete(notifier);
- notifier->v4l2_dev = NULL;
-
- return ret;
- }
-
for (i = 0; i < notifier->num_subdevs; i++) {
asd = notifier->subdevs[i];
mutex_lock(&list_lock);
ret = v4l2_async_notifier_try_all_subdevs(notifier);
- if (ret) {
- mutex_unlock(&list_lock);
- return ret;
- }
+ if (ret)
+ goto err_unbind;
- if (list_empty(¬ifier->waiting)) {
- ret = v4l2_async_notifier_call_complete(notifier);
- if (ret)
- goto err_complete;
- }
+ ret = v4l2_async_notifier_try_complete(notifier);
+ if (ret)
+ goto err_unbind;
/* Keep also completed notifiers on the list */
list_add(¬ifier->list, ¬ifier_list);
return 0;
-err_complete:
+err_unbind:
+ /*
+ * On failure, unbind all sub-devices registered through this notifier.
+ */
v4l2_async_notifier_unbind_all_subdevs(notifier);
mutex_unlock(&list_lock);
{
int ret;
- if (WARN_ON(!v4l2_dev))
+ if (WARN_ON(!v4l2_dev || notifier->sd))
return -EINVAL;
notifier->v4l2_dev = v4l2_dev;
}
EXPORT_SYMBOL(v4l2_async_notifier_register);
+int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
+ struct v4l2_async_notifier *notifier)
+{
+ int ret;
+
+ if (WARN_ON(!sd || notifier->v4l2_dev))
+ return -EINVAL;
+
+ notifier->sd = sd;
+
+ ret = __v4l2_async_notifier_register(notifier);
+ if (ret)
+ notifier->sd = NULL;
+
+ return ret;
+}
+EXPORT_SYMBOL(v4l2_async_subdev_notifier_register);
+
void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
{
- if (!notifier->v4l2_dev)
+ if (!notifier->v4l2_dev && !notifier->sd)
return;
mutex_lock(&list_lock);
- list_del(¬ifier->list);
-
v4l2_async_notifier_unbind_all_subdevs(notifier);
- mutex_unlock(&list_lock);
-
+ notifier->sd = NULL;
notifier->v4l2_dev = NULL;
+
+ list_del(¬ifier->list);
+
+ mutex_unlock(&list_lock);
}
EXPORT_SYMBOL(v4l2_async_notifier_unregister);
int v4l2_async_register_subdev(struct v4l2_subdev *sd)
{
+ struct v4l2_async_notifier *subdev_notifier;
struct v4l2_async_notifier *notifier;
int ret;
INIT_LIST_HEAD(&sd->async_list);
list_for_each_entry(notifier, ¬ifier_list, list) {
- struct v4l2_async_subdev *asd = v4l2_async_find_match(notifier,
- sd);
+ struct v4l2_device *v4l2_dev =
+ v4l2_async_notifier_find_v4l2_dev(notifier);
+ struct v4l2_async_subdev *asd;
int ret;
+ if (!v4l2_dev)
+ continue;
+
+ asd = v4l2_async_find_match(notifier, sd);
if (!asd)
continue;
ret = v4l2_async_match_notify(notifier, notifier->v4l2_dev, sd,
asd);
if (ret)
- goto err_unlock;
-
- if (!list_empty(¬ifier->waiting))
- goto out_unlock;
+ goto err_unbind;
- ret = v4l2_async_notifier_call_complete(notifier);
+ ret = v4l2_async_notifier_try_complete(notifier);
if (ret)
- goto err_cleanup;
+ goto err_unbind;
goto out_unlock;
}
return 0;
-err_cleanup:
- v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
+err_unbind:
+ /*
+ * Complete failed. Unbind the sub-devices bound through registering
+ * this async sub-device.
+ */
+ subdev_notifier = v4l2_async_find_subdev_notifier(sd);
+ if (subdev_notifier)
+ v4l2_async_notifier_unbind_all_subdevs(subdev_notifier);
+
+ if (sd->asd)
+ v4l2_async_notifier_call_unbind(notifier, sd, sd->asd);
v4l2_async_cleanup(sd);
-err_unlock:
mutex_unlock(&list_lock);
return ret;
/**
* struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations
* @bound: a subdevice driver has successfully probed one of the subdevices
- * @complete: all subdevices have been probed successfully
+ * @complete: All subdevices have been probed successfully. The complete
+ * callback is only executed for the root notifier.
* @unbind: a subdevice is leaving
*/
struct v4l2_async_notifier_operations {
* @num_subdevs: number of subdevices used in the subdevs array
* @max_subdevs: number of subdevices allocated in the subdevs array
* @subdevs: array of pointers to subdevice descriptors
- * @v4l2_dev: pointer to struct v4l2_device
+ * @v4l2_dev: v4l2_device of the root notifier, NULL otherwise
+ * @sd: sub-device that registered the notifier, NULL otherwise
+ * @parent: parent notifier
* @waiting: list of struct v4l2_async_subdev, waiting for their drivers
* @done: list of struct v4l2_subdev, already probed
* @list: member in a global list of notifiers
unsigned int max_subdevs;
struct v4l2_async_subdev **subdevs;
struct v4l2_device *v4l2_dev;
+ struct v4l2_subdev *sd;
+ struct v4l2_async_notifier *parent;
struct list_head waiting;
struct list_head done;
struct list_head list;
struct v4l2_async_notifier *notifier);
/**
+ * v4l2_async_subdev_notifier_register - registers a subdevice asynchronous
+ * notifier for a sub-device
+ *
+ * @sd: pointer to &struct v4l2_subdev
+ * @notifier: pointer to &struct v4l2_async_notifier
+ */
+int v4l2_async_subdev_notifier_register(struct v4l2_subdev *sd,
+ struct v4l2_async_notifier *notifier);
+
+/**
* v4l2_async_notifier_unregister - unregisters a subdevice asynchronous notifier
*
* @notifier: pointer to &struct v4l2_async_notifier