[PATCH v3 1/5] [media] videodev2: Add V4L2_BUF_FLAG_LAST

[Philipp Zabel <p.zabel@pengutronix.de>]

From: Peter Seiderer <ps.report@gmx.net>

This v4l2_buffer flag can be used by drivers to mark a capture buffer
as the last generated buffer, for example after a V4L2_DEC_CMD_STOP
command was issued.

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
Changes since v2:
 - Made V4L2_BUF_FLAG_LAST known to trace events
---
 Documentation/DocBook/media/v4l/io.xml | 10 ++++++++++
 include/trace/events/v4l2.h            |  3 ++-
 include/uapi/linux/videodev2.h         |  2 ++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml
index 1c17f80..f3b8bc0 100644
--- a/Documentation/DocBook/media/v4l/io.xml
+++ b/Documentation/DocBook/media/v4l/io.xml
@@ -1129,6 +1129,16 @@ 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>
 	  <row>
+	    <entry><constant>V4L2_BUF_FLAG_LAST</constant></entry>
+	    <entry>0x00100000</entry>
+	    <entry>Last buffer produced by the hardware. mem2mem codec drivers
+set this flag on the capture queue for the last buffer when the
+<link linkend="vidioc-querybuf">VIDIOC_QUERYBUF</link> or
+<link linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl is called. After the
+queue is drained, the <link linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl will
+not block anymore, but return an &EPIPE;.</entry>
+	  </row>
+	  <row>
 	    <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_MASK</constant></entry>
 	    <entry>0x0000e000</entry>
 	    <entry>Mask for timestamp types below. To test the
diff --git a/include/trace/events/v4l2.h b/include/trace/events/v4l2.h
index b9bb1f2..32c33aa 100644
--- a/include/trace/events/v4l2.h
+++ b/include/trace/events/v4l2.h
@@ -58,7 +58,8 @@
 		{ V4L2_BUF_FLAG_TIMESTAMP_MASK,	     "TIMESTAMP_MASK" },      \
 		{ V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN,   "TIMESTAMP_UNKNOWN" },   \
 		{ V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC, "TIMESTAMP_MONOTONIC" }, \
-		{ V4L2_BUF_FLAG_TIMESTAMP_COPY,	     "TIMESTAMP_COPY" })
+		{ V4L2_BUF_FLAG_TIMESTAMP_COPY,	     "TIMESTAMP_COPY" },      \
+		{ V4L2_BUF_FLAG_LAST,                "LAST" })
 
 #define show_timecode_flags(flags)					  \
 	__print_flags(flags, "|",					  \
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index fbdc360..c642c10 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -809,6 +809,8 @@ struct v4l2_buffer {
 #define V4L2_BUF_FLAG_TSTAMP_SRC_MASK		0x00070000
 #define V4L2_BUF_FLAG_TSTAMP_SRC_EOF		0x00000000
 #define V4L2_BUF_FLAG_TSTAMP_SRC_SOE		0x00010000
+/* mem2mem encoder/decoder */
+#define V4L2_BUF_FLAG_LAST			0x00100000
 
 /**
  * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor
-- 
2.1.4