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- <refentry id="media-ioc-setup-link">
- <refmeta>
- <refentrytitle>ioctl MEDIA_IOC_SETUP_LINK</refentrytitle>
- &manvol;
- </refmeta>
- <refnamediv>
- <refname>MEDIA_IOC_SETUP_LINK</refname>
- <refpurpose>Modify the properties of a link</refpurpose>
- </refnamediv>
- <refsynopsisdiv>
- <funcsynopsis>
- <funcprototype>
- <funcdef>int <function>ioctl</function></funcdef>
- <paramdef>int <parameter>fd</parameter></paramdef>
- <paramdef>int <parameter>request</parameter></paramdef>
- <paramdef>struct media_link_desc *<parameter>argp</parameter></paramdef>
- </funcprototype>
- </funcsynopsis>
- </refsynopsisdiv>
- <refsect1>
- <title>Arguments</title>
- <variablelist>
- <varlistentry>
- <term><parameter>fd</parameter></term>
- <listitem>
- <para>File descriptor returned by
- <link linkend='media-func-open'><function>open()</function></link>.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><parameter>request</parameter></term>
- <listitem>
- <para>MEDIA_IOC_SETUP_LINK</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><parameter>argp</parameter></term>
- <listitem>
- <para></para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
- <refsect1>
- <title>Description</title>
- <para>To change link properties applications fill a &media-link-desc; with
- link identification information (source and sink pad) and the new requested
- link flags. They then call the MEDIA_IOC_SETUP_LINK ioctl with a pointer to
- that structure.</para>
- <para>The only configurable property is the <constant>ENABLED</constant>
- link flag to enable/disable a link. Links marked with the
- <constant>IMMUTABLE</constant> link flag can not be enabled or disabled.
- </para>
- <para>Link configuration has no side effect on other links. If an enabled
- link at the sink pad prevents the link from being enabled, the driver
- returns with an &EBUSY;.</para>
- <para>Only links marked with the <constant>DYNAMIC</constant> link flag can
- be enabled/disabled while streaming media data. Attempting to enable or
- disable a streaming non-dynamic link will return an &EBUSY;.</para>
- <para>If the specified link can't be found the driver returns with an
- &EINVAL;.</para>
- </refsect1>
- <refsect1>
- &return-value;
- <variablelist>
- <varlistentry>
- <term><errorcode>EINVAL</errorcode></term>
- <listitem>
- <para>The &media-link-desc; references a non-existing link, or the
- link is immutable and an attempt to modify its configuration was made.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
- </refentry>
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