1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2 3.. _func-munmap: 4 5************* 6V4L2 munmap() 7************* 8 9Name 10==== 11 12v4l2-munmap - Unmap device memory 13 14 15Synopsis 16======== 17 18.. code-block:: c 19 20 #include <unistd.h> 21 #include <sys/mman.h> 22 23 24.. c:function:: int munmap( void *start, size_t length ) 25 :name: v4l2-munmap 26 27Arguments 28========= 29 30``start`` 31 Address of the mapped buffer as returned by the 32 :ref:`mmap() <func-mmap>` function. 33 34``length`` 35 Length of the mapped buffer. This must be the same value as given to 36 :ref:`mmap() <func-mmap>` and returned by the driver in the struct 37 :c:type:`v4l2_buffer` ``length`` field for the 38 single-planar API and in the struct 39 :c:type:`v4l2_plane` ``length`` field for the 40 multi-planar API. 41 42 43Description 44=========== 45 46Unmaps a previously with the :ref:`mmap() <func-mmap>` function mapped 47buffer and frees it, if possible. 48 49 50Return Value 51============ 52 53On success :ref:`munmap() <func-munmap>` returns 0, on failure -1 and the 54``errno`` variable is set appropriately: 55 56EINVAL 57 The ``start`` or ``length`` is incorrect, or no buffers have been 58 mapped yet. 59