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authorGuennadi Liakhovetski <g.liakhovetski@gmx.de>2011-09-28 08:10:58 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-11-03 18:28:27 -0200
commit55093284fb6f9009a339e522773417bdd54ec144 (patch)
treec9c91afddcec2fd5890e003e19558f7aa2018979 /Documentation/DocBook/media/v4l/io.xml
parent21db3e07e1c6302556ae3215ddf0539f5d763b62 (diff)
[media] V4L: document the new VIDIOC_CREATE_BUFS and VIDIOC_PREPARE_BUF ioctl()s
[mchehab@redhat.com: remove emacs format crap at the end of the new files] Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/DocBook/media/v4l/io.xml')
-rw-r--r--Documentation/DocBook/media/v4l/io.xml27
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml
index c57d1ec6291..3f47df1aa54 100644
--- a/Documentation/DocBook/media/v4l/io.xml
+++ b/Documentation/DocBook/media/v4l/io.xml
@@ -927,6 +927,33 @@ ioctl is called.</entry>
Applications set or clear this flag before calling the
<constant>VIDIOC_QBUF</constant> ioctl.</entry>
</row>
+ <row>
+ <entry><constant>V4L2_BUF_FLAG_PREPARED</constant></entry>
+ <entry>0x0400</entry>
+ <entry>The buffer has been prepared for I/O and can be queued by the
+application. Drivers set or clear this flag when the
+<link linkend="vidioc-querybuf">VIDIOC_QUERYBUF</link>, <link
+ linkend="vidioc-qbuf">VIDIOC_PREPARE_BUF</link>, <link
+ linkend="vidioc-qbuf">VIDIOC_QBUF</link> or <link
+ linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl is called.</entry>
+ </row>
+ <row>
+ <entry><constant>V4L2_BUF_FLAG_NO_CACHE_INVALIDATE</constant></entry>
+ <entry>0x0400</entry>
+ <entry>Caches do not have to be invalidated for this buffer.
+Typically applications shall use this flag if the data captured in the buffer
+is not going to be touched by the CPU, instead the buffer will, probably, be
+passed on to a DMA-capable hardware unit for further processing or output.
+</entry>
+ </row>
+ <row>
+ <entry><constant>V4L2_BUF_FLAG_NO_CACHE_CLEAN</constant></entry>
+ <entry>0x0800</entry>
+ <entry>Caches do not have to be cleaned for this buffer.
+Typically applications shall use this flag for output buffers if the data
+in this buffer has not been created by the CPU but by some DMA-capable unit,
+in which case caches have not been used.</entry>
+ </row>
</tbody>
</tgroup>
</table>