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

Sakari Ailus
2017-10-26T07:54:35Z

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.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
drivers/media/v4l2-core/v4l2-async.c | 71 ++++++++++++++++++++++++++----------
1 file changed, 52 insertions(+), 19 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 1b536d68cedf..eb31d96254d1 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 +152,31 @@ 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) {
+ mutex_unlock(&list_lock);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
static void v4l2_async_cleanup(struct v4l2_subdev *sd)
{
v4l2_device_unregister_subdev(sd);
@@ -172,18 +198,15 @@ 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 +239,10 @@ 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 +265,23 @@ 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 +356,8 @@ 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