linux/Documentation/userspace-api/media/dvb/dmx-set-buffer-size.rst

.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.dmx

.. _DMX_SET_BUFFER_SIZE:

===================
DMX_SET_BUFFER_SIZE
===================

Name
----

DMX_SET_BUFFER_SIZE

Synopsis
--------

.. c:macro:: DMX_SET_BUFFER_SIZE

``int ioctl(int fd, DMX_SET_BUFFER_SIZE, unsigned long size)``

Arguments
---------

``fd``
    File descriptor returned by :c:func:`open()`.

``size``
    Unsigned long size

Description
-----------

This ioctl call is used to set the size of the circular buffer used for
filtered data. The default size is two maximum sized sections, i.e. if
this function is not called a buffer size of ``2 * 4096`` bytes will be
used.

Return Value
------------

On success 0 is returned.

On error -1 is returned, and the ``errno`` variable is set
appropriately.

The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
media: docs: use the new SPDX header for GFDL-1.1 on *.rst files SPDX v3.10 gained support for GFDL-1.1 with no invariant sections: https://spdx.org/licenses/GFDL-1.1-no-invariants-or-later.html So, remove the license text, replacing them by this new SPDX license. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 2020-08-26 09:03:09 +02:00			`.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later`
media: docs: make DVB documents more compatible with Sphinx 3.1+ Sphinx 3.x broke support for the cdomain.py extension, as the c domain code was rewritten. Due to that, the c tags need to be re-written, in order to use the new c domain notation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 2020-09-24 16:56:00 +02:00			`.. c:namespace:: DTV.dmx`
media: add SPDX header to media uAPI files All those files are under GFDL 1.1 or later, with no invariant sections. Tag them as such. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> 2018-08-30 10:15:26 -04:00
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00			`.. _DMX_SET_BUFFER_SIZE:`

doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 07:58:48 -03:00			`===================`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00			`DMX_SET_BUFFER_SIZE`
			`===================`

doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 15:14:35 -03:00			`Name`
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 07:58:48 -03:00			`----`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 07:58:48 -03:00			`DMX_SET_BUFFER_SIZE`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 15:14:35 -03:00			`Synopsis`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00			`--------`

media: docs: make DVB documents more compatible with Sphinx 3.1+ Sphinx 3.x broke support for the cdomain.py extension, as the c domain code was rewritten. Due to that, the c tags need to be re-written, in order to use the new c domain notation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 2020-09-24 16:56:00 +02:00			`.. c:macro:: DMX_SET_BUFFER_SIZE`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00
media: docs: make DVB documents more compatible with Sphinx 3.1+ Sphinx 3.x broke support for the cdomain.py extension, as the c domain code was rewritten. Due to that, the c tags need to be re-written, in order to use the new c domain notation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 2020-09-24 16:56:00 +02:00			``int ioctl(int fd, DMX_SET_BUFFER_SIZE, unsigned long size)``
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 15:14:35 -03:00			`Arguments`
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 07:58:48 -03:00			`---------`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00
[media] docs-rst: Convert DVB uAPI to use C function references Name all ioctl references and make them match the ioctls that are documented. That will improve the cross-reference index, as it will have all ioctls and syscalls there. While here, improve the documentation, marking the deprecated ioctls, and making the non-deprecated ones more like the rest of the media book. Also, add a notice for ioctls that still require documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-08-19 16:56:15 -03:00			``fd``
media: docs: make DVB documents more compatible with Sphinx 3.1+ Sphinx 3.x broke support for the cdomain.py extension, as the c domain code was rewritten. Due to that, the c tags need to be re-written, in order to use the new c domain notation. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 2020-09-24 16:56:00 +02:00			File descriptor returned by :c:func:`open()`.
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00
[media] docs-rst: Convert DVB uAPI to use C function references Name all ioctl references and make them match the ioctls that are documented. That will improve the cross-reference index, as it will have all ioctls and syscalls there. While here, improve the documentation, marking the deprecated ioctls, and making the non-deprecated ones more like the rest of the media book. Also, add a notice for ioctls that still require documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-08-19 16:56:15 -03:00			``size``
			`Unsigned long size`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00
doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 15:14:35 -03:00			`Description`
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 07:58:48 -03:00			`-----------`

			`This ioctl call is used to set the size of the circular buffer used for`
			`filtered data. The default size is two maximum sized sections, i.e. if`
media: dvb uAPI docs: minor editorial changes Do minor editorial changes to improve documentation readability: - mark literals as such; - add table markups to hint sizes; - define what PES means; - instead of hardcoding devnode numbers to zero (like adapter0/) use a question mark, to indicate that multiple devnodes may exist; - add cross-references where useful. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-09-01 12:21:49 -04:00			this function is not called a buffer size of ``2 * 4096`` bytes will be
doc-rst: linux_tv: reformat all syscall pages The syscall pages are written to be used also as man-pages. However, they don't match the format used by kernel-doc generated pages from DocBook. Rewrite them to match it. One side effect is that now all such pages at the book will have the same format, reducing the format differences between DVB and the other parts of the book. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 07:58:48 -03:00			`used.`

doc-rst: linux_tv: don't use uppercases for syscall sections On the syscall conversions, we used uppercase for the sections, but this is too bold. So, convert them to Camel Case, as it looks visually better. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 15:14:35 -03:00			`Return Value`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00			`------------`

media: dvb uAPI docs: adjust return value ioctl descriptions There are several issues on the return value for ioctls: - Text is confusing; - Some error codes don't exist; - The non-generic error codes should come before the text that points to the generic error codes; - Tables don't contain column size hints; - Some references are not marked as such. Correct them. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2017-09-01 12:15:43 -04:00			`On success 0 is returned.`

			On error -1 is returned, and the ``errno`` variable is set
			`appropriately.`

			`The generic error codes are described at the`
doc-rst: linux_tv: split DVB function call documentation Just like V4L, split the DVB function calls into one file per system call. This is a requirement for the man pages creator on Sphinx to work, and makes the document easier to maintain. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> 2016-07-05 10:37:31 -03:00			:ref:`Generic Error Codes <gen-errors>` chapter.