[PATCH v16.1 17/32] v4l: async: Prepare for async sub-device notifiers

[Sakari Ailus]

Refactor the V4L2 async framework a little in preparation for async
sub-device notifiers. This avoids making some structural changes in the
patch actually implementing sub-device notifiers, making that patch easier
to review.

Signed-off-by: Sakari Ailus <sakari.ai...@linux.intel.com>
Acked-by: Hans Verkuil <hans.verk...@cisco.com>
---
 drivers/media/v4l2-core/v4l2-async.c | 69 ++++++++++++++++++++++++++----------
 1 file changed, 50 insertions(+), 19 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c 
b/drivers/media/v4l2-core/v4l2-async.c
index 1b536d68cedf..6265717769d2 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -125,12 +125,13 @@ static struct v4l2_async_subdev *v4l2_async_find_match(
 }
 
 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)
 {
        int ret;
 
-       ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
+       ret = v4l2_device_register_subdev(v4l2_dev, sd);
        if (ret < 0)
                return ret;
 
@@ -151,6 +152,29 @@ static int v4l2_async_match_notify(struct 
v4l2_async_notifier *notifier,
        return 0;
 }
 
+/* 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;
+
+       list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
+               struct v4l2_async_subdev *asd;
+               int ret;
+
+               asd = v4l2_async_find_match(notifier, sd);
+               if (!asd)
+                       continue;
+
+               ret = v4l2_async_match_notify(notifier, v4l2_dev, sd, asd);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return 0;
+}
+
 static void v4l2_async_cleanup(struct v4l2_subdev *sd)
 {
        v4l2_device_unregister_subdev(sd);
@@ -172,18 +196,15 @@ static void v4l2_async_notifier_unbind_all_subdevs(
        }
 }
 
-int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
-                                struct v4l2_async_notifier *notifier)
+static int __v4l2_async_notifier_register(struct v4l2_async_notifier *notifier)
 {
-       struct v4l2_subdev *sd, *tmp;
        struct v4l2_async_subdev *asd;
        int ret;
        int i;
 
-       if (!v4l2_dev || notifier->num_subdevs > V4L2_MAX_SUBDEVS)
+       if (notifier->num_subdevs > V4L2_MAX_SUBDEVS)
                return -EINVAL;
 
-       notifier->v4l2_dev = v4l2_dev;
        INIT_LIST_HEAD(&notifier->waiting);
        INIT_LIST_HEAD(&notifier->done);
 
@@ -216,18 +237,10 @@ int v4l2_async_notifier_register(struct v4l2_device 
*v4l2_dev,
 
        mutex_lock(&list_lock);
 
-       list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
-               int ret;
-
-               asd = v4l2_async_find_match(notifier, sd);
-               if (!asd)
-                       continue;
-
-               ret = v4l2_async_match_notify(notifier, sd, asd);
-               if (ret < 0) {
-                       mutex_unlock(&list_lock);
-                       return ret;
-               }
+       ret = v4l2_async_notifier_try_all_subdevs(notifier);
+       if (ret) {
+               mutex_unlock(&list_lock);
+               return ret;
        }
 
        if (list_empty(&notifier->waiting)) {
@@ -250,6 +263,23 @@ int v4l2_async_notifier_register(struct v4l2_device 
*v4l2_dev,
 
        return ret;
 }
+
+int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
+                                struct v4l2_async_notifier *notifier)
+{
+       int ret;
+
+       if (WARN_ON(!v4l2_dev))
+               return -EINVAL;
+
+       notifier->v4l2_dev = v4l2_dev;
+
+       ret = __v4l2_async_notifier_register(notifier);
+       if (ret)
+               notifier->v4l2_dev = NULL;
+
+       return ret;
+}
 EXPORT_SYMBOL(v4l2_async_notifier_register);
 
 void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
@@ -324,7 +354,8 @@ int v4l2_async_register_subdev(struct v4l2_subdev *sd)
                if (!asd)
                        continue;
 
-               ret = v4l2_async_match_notify(notifier, sd, asd);
+               ret = v4l2_async_match_notify(notifier, notifier->v4l2_dev, sd,
+                                             asd);
                if (ret)
                        goto err_unlock;
 
-- 
2.11.0