On 04/07/2014 10:32 AM, Pawel Osciak wrote:
On Tue, Mar 11, 2014 at 6:20 AM, Hans Verkuil hverk...@xs4all.nl wrote:
From: Hans Verkuil hans.verk...@cisco.com
When using write() to write data to an output video node the vb2 core
should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
I'm confused. Shouldn't we be saving the existing timestamp from the buffer if
V4L2_BUF_FLAG_TIMESTAMP_COPY is true, instead of getting it from
v4l2_get_timestamp()?
When using the write() file operation the application has no way of setting the
timestamp. So it is uninitialized and the reader on the other side receives an
uninitialized (or 0, I'm not sure) timestamp. So __vb2_perform_fileio() has to
fill in a valid timestamp instead.
It's a corner case.
Regards,
Hans
else is able to provide this information with the write() operation.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/videobuf2-core.c | 6 ++
1 file changed, 6 insertions(+)
diff --git a/drivers/media/v4l2-core/videobuf2-core.c
b/drivers/media/v4l2-core/videobuf2-core.c
index e38b45e..afd1268 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -22,6 +22,7 @@
#include media/v4l2-dev.h
#include media/v4l2-fh.h
#include media/v4l2-event.h
+#include media/v4l2-common.h
#include media/videobuf2-core.h
static int debug;
@@ -2767,6 +2768,9 @@ static size_t __vb2_perform_fileio(struct vb2_queue
*q, char __user *data, size_
{
struct vb2_fileio_data *fileio;
struct vb2_fileio_buf *buf;
+ bool set_timestamp = !read
+ (q-timestamp_flags V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
+ V4L2_BUF_FLAG_TIMESTAMP_COPY;
int ret, index;
dprintk(3, file io: mode %s, offset %ld, count %zd, %sblocking\n,
@@ -2868,6 +2872,8 @@ static size_t __vb2_perform_fileio(struct vb2_queue
*q, char __user *data, size_
fileio-b.memory = q-memory;
fileio-b.index = index;
fileio-b.bytesused = buf-pos;
+ if (set_timestamp)
+ v4l2_get_timestamp(fileio-b.timestamp);
ret = vb2_internal_qbuf(q, fileio-b);
dprintk(5, file io: vb2_internal_qbuf result: %d\n, ret);
if (ret)
--
1.9.0
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
