forked from Minki/linux
c6401af669
This removes comment tags intended for emacs configuration from 67 files in the Media API DocBook. Such comments are not really helpful and violate the coding style rules. Signed-off-by: Sylwester Nawrocki <snjw23@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
77 lines
2.2 KiB
XML
77 lines
2.2 KiB
XML
<refentry id="func-munmap">
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<refmeta>
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<refentrytitle>V4L2 munmap()</refentrytitle>
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&manvol;
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</refmeta>
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<refnamediv>
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<refname>v4l2-munmap</refname>
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<refpurpose>Unmap device memory</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<funcsynopsis>
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<funcsynopsisinfo>
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#include <unistd.h>
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#include <sys/mman.h></funcsynopsisinfo>
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<funcprototype>
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<funcdef>int <function>munmap</function></funcdef>
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<paramdef>void *<parameter>start</parameter></paramdef>
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<paramdef>size_t <parameter>length</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Arguments</title>
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<variablelist>
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<varlistentry>
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<term><parameter>start</parameter></term>
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<listitem>
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<para>Address of the mapped buffer as returned by the
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&func-mmap; function.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>length</parameter></term>
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<listitem>
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<para>Length of the mapped buffer. This must be the same
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value as given to <function>mmap()</function> and returned by the
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driver in the &v4l2-buffer; <structfield>length</structfield>
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field for the single-planar API and in the &v4l2-plane;
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<structfield>length</structfield> field for the multi-planar API.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1>
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<title>Description</title>
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<para>Unmaps a previously with the &func-mmap; function mapped
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buffer and frees it, if possible. <!-- ? This function (not freeing)
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has no impact on I/O in progress, specifically it does not imply
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&VIDIOC-STREAMOFF; to terminate I/O. Unmapped buffers can still be
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enqueued, dequeued or queried, they are just not accessible by the
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application.--></para>
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</refsect1>
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<refsect1>
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<title>Return Value</title>
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<para>On success <function>munmap()</function> returns 0, on
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failure -1 and the <varname>errno</varname> variable is set
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appropriately:</para>
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<variablelist>
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<varlistentry>
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<term><errorcode>EINVAL</errorcode></term>
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<listitem>
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<para>The <parameter>start</parameter> or
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<parameter>length</parameter> is incorrect, or no buffers have been
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mapped yet.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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</refentry>
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