48 lines
1.2 KiB
ReStructuredText
48 lines
1.2 KiB
ReStructuredText
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
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.. c:namespace:: V4L
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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:macro:: VIDIOC_LOG_STATUS
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``int ioctl(int fd, 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 :c: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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