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| author | Javier Martinez Canillas <javier@osg.samsung.com> | 2016-05-31 13:56:08 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-08 16:16:55 -0300 |
| commit | bcdb9040df9e1e2a16252791c43f9c40c2927dd3 (patch) | |
| tree | 4342054e6a824513127bffc9847776af1724f271 /Documentation/DocBook | |
| parent | e1f1cb8598a922d1754eb37adfad92f01b863e3e (diff) | |
| download | linux-bcdb9040df9e1e2a16252791c43f9c40c2927dd3.tar.bz2 | |
[media] DocBook: mention the memory type to be set for all streaming I/O
The DMA buffer importing streaming I/O section mentions the memory type
value that has to be set when calling the VIDIOC_REQBUFS ioctl but this
isn't mentioned in neither the Memory Mapping nor User Pointer sections.
A user can know the values by looking at the examples but it's better
to explicitly mention in the documentation, and also makes all sections
about streaming I/O methods more consistent.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'Documentation/DocBook')
| -rw-r--r-- | Documentation/DocBook/media/v4l/io.xml | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index e09025db92bd..21a3dde8f95d 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -88,7 +88,7 @@ function.<footnote> <structfield>capabilities</structfield> field of &v4l2-capability; returned by the &VIDIOC-QUERYCAP; ioctl is set. There are two streaming methods, to determine if the memory mapping flavor is -supported applications must call the &VIDIOC-REQBUFS; ioctl.</para> +supported applications must call the &VIDIOC-REQBUFS; ioctl with the memory type set to <constant>V4L2_MEMORY_MMAP</constant>.</para> <para>Streaming is an I/O method where only pointers to buffers are exchanged between application and driver, the data itself is not @@ -369,7 +369,7 @@ rest should be evident.</para> <structfield>capabilities</structfield> field of &v4l2-capability; returned by the &VIDIOC-QUERYCAP; ioctl is set. If the particular user pointer method (not only memory mapping) is supported must be -determined by calling the &VIDIOC-REQBUFS; ioctl.</para> +determined by calling the &VIDIOC-REQBUFS; ioctl with the memory type set to <constant>V4L2_MEMORY_USERPTR</constant>.</para> <para>This I/O method combines advantages of the read/write and memory mapping methods. Buffers (planes) are allocated by the application |