media: vb2: remove vb2_ops_wait_prepare/finish helpers

Since vb2 now relies on the presence of the vb2_queue lock
field and there are no more drivers that use these helpers, it is safe
to drop them.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

3 files changed, 4 insertions, 36 deletions

diff --git a/Documentation/driver-api/media/v4l2-dev.rst b/Documentation/driver-api/media/v4l2-dev.rst
index d5cb19b21a9f..dd239ad42051 100644
--- a/Documentation/driver-api/media/v4l2-dev.rst
+++ b/Documentation/driver-api/media/v4l2-dev.rst
@@ -157,10 +157,10 @@ changing the e.g. exposure of the webcam.
 Of course, you can always do all the locking yourself by leaving both lock
 pointers at ``NULL``.
 
-In the case of :ref:`videobuf2 <vb2_framework>` you will need to implement the
-``wait_prepare()`` and ``wait_finish()`` callbacks to unlock/lock if applicable.
-If you use the ``queue->lock`` pointer, then you can use the helper functions
-:c:func:`vb2_ops_wait_prepare` and :c:func:`vb2_ops_wait_finish`.
+In the case of :ref:`videobuf2 <vb2_framework>` you must set the ``queue->lock``
+pointer to the lock you use to serialize the queuing ioctls. This ensures that
+that lock is released while waiting in ``VIDIOC_DQBUF`` for a buffer to arrive,
+and it is retaken afterwards.
 
 The implementation of a hotplug disconnect should also take the lock from
 :c:type:`video_device` before calling v4l2_device_disconnect. If you are also
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 83862d57b126..4baded4fd3b8 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -1302,20 +1302,6 @@ void vb2_video_unregister_device(struct video_device *vdev)
 }
 EXPORT_SYMBOL_GPL(vb2_video_unregister_device);
 
-/* vb2_ops helpers. Only use if vq->lock is non-NULL. */
-
-void vb2_ops_wait_prepare(struct vb2_queue *vq)
-{
-	mutex_unlock(vq->lock);
-}
-EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
-
-void vb2_ops_wait_finish(struct vb2_queue *vq)
-{
-	mutex_lock(vq->lock);
-}
-EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
-
 /*
  * Note that this function is called during validation time and
  * thus the req_queue_mutex is held to ensure no request objects
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 77ce8238ab30..71d2864fb235 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -367,24 +367,6 @@ unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
  */
 void vb2_video_unregister_device(struct video_device *vdev);
 
-/**
- * vb2_ops_wait_prepare - helper function to lock a struct &vb2_queue
- *
- * @vq: pointer to &struct vb2_queue
- *
- * ..note:: only use if vq->lock is non-NULL.
- */
-void vb2_ops_wait_prepare(struct vb2_queue *vq);
-
-/**
- * vb2_ops_wait_finish - helper function to unlock a struct &vb2_queue
- *
- * @vq: pointer to &struct vb2_queue
- *
- * ..note:: only use if vq->lock is non-NULL.
- */
-void vb2_ops_wait_finish(struct vb2_queue *vq);
-
 struct media_request;
 int vb2_request_validate(struct media_request *req);
 void vb2_request_queue(struct media_request *req);