1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2*4882a593Smuzhiyun.. c:namespace:: V4L 3*4882a593Smuzhiyun 4*4882a593Smuzhiyun.. _func-munmap: 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun************* 7*4882a593SmuzhiyunV4L2 munmap() 8*4882a593Smuzhiyun************* 9*4882a593Smuzhiyun 10*4882a593SmuzhiyunName 11*4882a593Smuzhiyun==== 12*4882a593Smuzhiyun 13*4882a593Smuzhiyunv4l2-munmap - Unmap device memory 14*4882a593Smuzhiyun 15*4882a593SmuzhiyunSynopsis 16*4882a593Smuzhiyun======== 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun.. code-block:: c 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun #include <unistd.h> 21*4882a593Smuzhiyun #include <sys/mman.h> 22*4882a593Smuzhiyun 23*4882a593Smuzhiyun.. c:function:: int munmap( void *start, size_t length ) 24*4882a593Smuzhiyun 25*4882a593SmuzhiyunArguments 26*4882a593Smuzhiyun========= 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun``start`` 29*4882a593Smuzhiyun Address of the mapped buffer as returned by the 30*4882a593Smuzhiyun :c:func:`mmap()` function. 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun``length`` 33*4882a593Smuzhiyun Length of the mapped buffer. This must be the same value as given to 34*4882a593Smuzhiyun :c:func:`mmap()` and returned by the driver in the struct 35*4882a593Smuzhiyun :c:type:`v4l2_buffer` ``length`` field for the 36*4882a593Smuzhiyun single-planar API and in the struct 37*4882a593Smuzhiyun :c:type:`v4l2_plane` ``length`` field for the 38*4882a593Smuzhiyun multi-planar API. 39*4882a593Smuzhiyun 40*4882a593SmuzhiyunDescription 41*4882a593Smuzhiyun=========== 42*4882a593Smuzhiyun 43*4882a593SmuzhiyunUnmaps a previously with the :c:func:`mmap()` function mapped 44*4882a593Smuzhiyunbuffer and frees it, if possible. 45*4882a593Smuzhiyun 46*4882a593SmuzhiyunReturn Value 47*4882a593Smuzhiyun============ 48*4882a593Smuzhiyun 49*4882a593SmuzhiyunOn success :c:func:`munmap()` returns 0, on failure -1 and the 50*4882a593Smuzhiyun``errno`` variable is set appropriately: 51*4882a593Smuzhiyun 52*4882a593SmuzhiyunEINVAL 53*4882a593Smuzhiyun The ``start`` or ``length`` is incorrect, or no buffers have been 54*4882a593Smuzhiyun mapped yet. 55