From 479bc5a8c662e9d9de47e95ee26ebaf15f36a771 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 6 Sep 2017 10:48:33 -0400 Subject: media: v4l: async: Allow async notifier register call succeed with no subdevs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The information on how many async sub-devices would be bindable to a notifier is typically dependent on information from platform firmware and it's not driver's business to be aware of that. Many V4L2 main drivers are perfectly usable (and useful) without async sub-devices and so if there aren't any around, just proceed call the notifier's complete callback immediately without registering the notifier itself. If a driver needs to check whether there are async sub-devices available, it can be done by inspecting the notifier's num_subdevs field which tells the number of async sub-devices. Signed-off-by: Sakari Ailus Acked-by: Hans Verkuil Acked-by: Niklas Söderlund Reviewed-by: Sebastian Reichel Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-async.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index 46db85685894..1b536d68cedf 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -180,14 +180,22 @@ int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev, int ret; int i; - if (!v4l2_dev || !notifier->num_subdevs || - notifier->num_subdevs > V4L2_MAX_SUBDEVS) + if (!v4l2_dev || notifier->num_subdevs > V4L2_MAX_SUBDEVS) return -EINVAL; notifier->v4l2_dev = v4l2_dev; 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]; -- cgit v1.2.3-70-g09d2