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