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