1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: V4L
3
4.. _VIDIOC_LOG_STATUS:
5
6***********************
7ioctl VIDIOC_LOG_STATUS
8***********************
9
10Name
11====
12
13VIDIOC_LOG_STATUS - Log driver status information
14
15Synopsis
16========
17
18.. c:macro:: VIDIOC_LOG_STATUS
19
20``int ioctl(int fd, VIDIOC_LOG_STATUS)``
21
22Arguments
23=========
24
25``fd``
26    File descriptor returned by :c:func:`open()`.
27
28Description
29===========
30
31As the video/audio devices become more complicated it becomes harder to
32debug problems. When this ioctl is called the driver will output the
33current device status to the kernel log. This is particular useful when
34dealing with problems like no sound, no video and incorrectly tuned
35channels. Also many modern devices autodetect video and audio standards
36and this ioctl will report what the device thinks what the standard is.
37Mismatches may give an indication where the problem is.
38
39This ioctl is optional and not all drivers support it. It was introduced
40in Linux 2.6.15.
41
42Return Value
43============
44
45On success 0 is returned, on error -1 and the ``errno`` variable is set
46appropriately. The generic error codes are described at the
47:ref:`Generic Error Codes <gen-errors>` chapter.
48