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Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/media/v4l2-dev.rst | 8 |
1 files changed, 4 insertions, 4 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 |