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1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later2.. c:namespace:: V4L3 4.. _func-munmap:5 6*************7V4L2 munmap()8*************9 10Name11====12 13v4l2-munmap - Unmap device memory14 15Synopsis16========17 18.. code-block:: c19 20 #include <unistd.h>21 #include <sys/mman.h>22 23.. c:function:: int munmap( void *start, size_t length )24 25Arguments26=========27 28``start``29 Address of the mapped buffer as returned by the30 :c:func:`mmap()` function.31 32``length``33 Length of the mapped buffer. This must be the same value as given to34 :c:func:`mmap()` and returned by the driver in the struct35 :c:type:`v4l2_buffer` ``length`` field for the36 single-planar API and in the struct37 :c:type:`v4l2_plane` ``length`` field for the38 multi-planar API.39 40Description41===========42 43Unmaps a previously with the :c:func:`mmap()` function mapped44buffer and frees it, if possible.45 46Return Value47============48 49On success :c:func:`munmap()` returns 0, on failure -1 and the50``errno`` variable is set appropriately:51 52EINVAL53 The ``start`` or ``length`` is incorrect, or no buffers have been54 mapped yet.55