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- .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
- .. c:namespace:: V4L
- .. _func-munmap:
- *************
- V4L2 munmap()
- *************
- Name
- ====
- v4l2-munmap - Unmap device memory
- Synopsis
- ========
- .. code-block:: c
- #include <unistd.h>
- #include <sys/mman.h>
- .. c:function:: int munmap( void *start, size_t length )
- Arguments
- =========
- ``start``
- Address of the mapped buffer as returned by the
- :c:func:`mmap()` function.
- ``length``
- Length of the mapped buffer. This must be the same value as given to
- :c:func:`mmap()` and returned by the driver in the struct
- :c:type:`v4l2_buffer` ``length`` field for the
- single-planar API and in the struct
- :c:type:`v4l2_plane` ``length`` field for the
- multi-planar API.
- Description
- ===========
- Unmaps a previously with the :c:func:`mmap()` function mapped
- buffer and frees it, if possible.
- Return Value
- ============
- On success :c:func:`munmap()` returns 0, on failure -1 and the
- ``errno`` variable is set appropriately:
- EINVAL
- The ``start`` or ``length`` is incorrect, or no buffers have been
- mapped yet.
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