Based on kernel version 3.0.4. Page generated on 2011-10-03 22:07 EST.
1 <refentry id="media-ioc-setup-link"> 2 <refmeta> 3 <refentrytitle>ioctl MEDIA_IOC_SETUP_LINK</refentrytitle> 4 &manvol; 5 </refmeta> 6 7 <refnamediv> 8 <refname>MEDIA_IOC_SETUP_LINK</refname> 9 <refpurpose>Modify the properties of a link</refpurpose> 10 </refnamediv> 11 12 <refsynopsisdiv> 13 <funcsynopsis> 14 <funcprototype> 15 <funcdef>int <function>ioctl</function></funcdef> 16 <paramdef>int <parameter>fd</parameter></paramdef> 17 <paramdef>int <parameter>request</parameter></paramdef> 18 <paramdef>struct media_link_desc *<parameter>argp</parameter></paramdef> 19 </funcprototype> 20 </funcsynopsis> 21 </refsynopsisdiv> 22 23 <refsect1> 24 <title>Arguments</title> 25 26 <variablelist> 27 <varlistentry> 28 <term><parameter>fd</parameter></term> 29 <listitem> 30 <para>File descriptor returned by 31 <link linkend='media-func-open'><function>open()</function></link>.</para> 32 </listitem> 33 </varlistentry> 34 <varlistentry> 35 <term><parameter>request</parameter></term> 36 <listitem> 37 <para>MEDIA_IOC_SETUP_LINK</para> 38 </listitem> 39 </varlistentry> 40 <varlistentry> 41 <term><parameter>argp</parameter></term> 42 <listitem> 43 <para></para> 44 </listitem> 45 </varlistentry> 46 </variablelist> 47 </refsect1> 48 49 <refsect1> 50 <title>Description</title> 51 52 <para>To change link properties applications fill a &media-link-desc; with 53 link identification information (source and sink pad) and the new requested 54 link flags. They then call the MEDIA_IOC_SETUP_LINK ioctl with a pointer to 55 that structure.</para> 56 <para>The only configurable property is the <constant>ENABLED</constant> 57 link flag to enable/disable a link. Links marked with the 58 <constant>IMMUTABLE</constant> link flag can not be enabled or disabled. 59 </para> 60 <para>Link configuration has no side effect on other links. If an enabled 61 link at the sink pad prevents the link from being enabled, the driver 62 returns with an &EBUSY;.</para> 63 <para>Only links marked with the <constant>DYNAMIC</constant> link flag can 64 be enabled/disabled while streaming media data. Attempting to enable or 65 disable a streaming non-dynamic link will return an &EBUSY;.</para> 66 <para>If the specified link can't be found the driver returns with an 67 &EINVAL;.</para> 68 </refsect1> 69 70 <refsect1> 71 &return-value; 72 73 <variablelist> 74 <varlistentry> 75 <term><errorcode>EBUSY</errorcode></term> 76 <listitem> 77 <para>The link properties can't be changed because the link is 78 currently busy. This can be caused, for instance, by an active media 79 stream (audio or video) on the link. The ioctl shouldn't be retried if 80 no other action is performed before to fix the problem.</para> 81 </listitem> 82 </varlistentry> 83 <varlistentry> 84 <term><errorcode>EINVAL</errorcode></term> 85 <listitem> 86 <para>The &media-link-desc; references a non-existing link, or the 87 link is immutable and an attempt to modify its configuration was made. 88 </para> 89 </listitem> 90 </varlistentry> 91 </variablelist> 92 </refsect1> 93 </refentry>
