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author | Jiri Kosina <jkosina@suse.cz> | 2011-11-13 20:55:35 +0100 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2011-11-13 20:55:53 +0100 |
commit | 2290c0d06d82faee87b1ab2d9d4f7bf81ef64379 (patch) | |
tree | e075e4d5534193f28e6059904f61e5ca03958d3c /Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml | |
parent | 4da669a2e3e5bc70b30a0465f3641528681b5f77 (diff) | |
parent | 52e4c2a05256cb83cda12f3c2137ab1533344edb (diff) | |
download | talos-op-linux-2290c0d06d82faee87b1ab2d9d4f7bf81ef64379.tar.gz talos-op-linux-2290c0d06d82faee87b1ab2d9d4f7bf81ef64379.zip |
Merge branch 'master' into for-next
Sync with Linus tree to have 157550ff ("mtd: add GPMI-NAND driver
in the config and Makefile") as I have patch depending on that one.
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml b/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml new file mode 100644 index 000000000000..7bde698760e4 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml @@ -0,0 +1,88 @@ +<refentry id="vidioc-prepare-buf"> + <refmeta> + <refentrytitle>ioctl VIDIOC_PREPARE_BUF</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_PREPARE_BUF</refname> + <refpurpose>Prepare a buffer for I/O</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 v4l2_buffer *<parameter>argp</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Arguments</title> + + <variablelist> + <varlistentry> + <term><parameter>fd</parameter></term> + <listitem> + <para>&fd;</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>request</parameter></term> + <listitem> + <para>VIDIOC_PREPARE_BUF</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <para>Applications can optionally call the +<constant>VIDIOC_PREPARE_BUF</constant> ioctl to pass ownership of the buffer +to the driver before actually enqueuing it, using the +<constant>VIDIOC_QBUF</constant> ioctl, and to prepare it for future I/O. +Such preparations may include cache invalidation or cleaning. Performing them +in advance saves time during the actual I/O. In case such cache operations are +not required, the application can use one of +<constant>V4L2_BUF_FLAG_NO_CACHE_INVALIDATE</constant> and +<constant>V4L2_BUF_FLAG_NO_CACHE_CLEAN</constant> flags to skip the respective +step.</para> + + <para>The <structname>v4l2_buffer</structname> structure is +specified in <xref linkend="buffer" />.</para> + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>EBUSY</errorcode></term> + <listitem> + <para>File I/O is in progress.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>The buffer <structfield>type</structfield> is not +supported, or the <structfield>index</structfield> is out of bounds, +or no buffers have been allocated yet, or the +<structfield>userptr</structfield> or +<structfield>length</structfield> are invalid.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> |