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54f38fcae5
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee38 ("docs: Create a user-space API guide").
As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.
Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
57 lines
1.6 KiB
ReStructuredText
57 lines
1.6 KiB
ReStructuredText
.. Permission is granted to copy, distribute and/or modify this
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.. document under the terms of the GNU Free Documentation License,
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.. Version 1.1 or any later version published by the Free Software
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.. Foundation, with no Invariant Sections, no Front-Cover Texts
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.. and no Back-Cover Texts. A copy of the license is included at
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.. Documentation/userspace-api/media/fdl-appendix.rst.
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..
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.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
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.. _VIDIOC_LOG_STATUS:
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***********************
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ioctl VIDIOC_LOG_STATUS
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***********************
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Name
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====
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VIDIOC_LOG_STATUS - Log driver status information
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Synopsis
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========
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.. c:function:: int ioctl( int fd, VIDIOC_LOG_STATUS)
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:name: VIDIOC_LOG_STATUS
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Arguments
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=========
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``fd``
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File descriptor returned by :ref:`open() <func-open>`.
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Description
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===========
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As the video/audio devices become more complicated it becomes harder to
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debug problems. When this ioctl is called the driver will output the
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current device status to the kernel log. This is particular useful when
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dealing with problems like no sound, no video and incorrectly tuned
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channels. Also many modern devices autodetect video and audio standards
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and this ioctl will report what the device thinks what the standard is.
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Mismatches may give an indication where the problem is.
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This ioctl is optional and not all drivers support it. It was introduced
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in Linux 2.6.15.
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Return Value
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============
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On success 0 is returned, on error -1 and the ``errno`` variable is set
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appropriately. The generic error codes are described at the
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:ref:`Generic Error Codes <gen-errors>` chapter.
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