| .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later |
| .. c:namespace:: V4L |
| |
| .. _VIDIOC_LOG_STATUS: |
| |
| *********************** |
| ioctl VIDIOC_LOG_STATUS |
| *********************** |
| |
| Name |
| ==== |
| |
| VIDIOC_LOG_STATUS - Log driver status information |
| |
| Synopsis |
| ======== |
| |
| .. c:macro:: VIDIOC_LOG_STATUS |
| |
| ``int ioctl(int fd, VIDIOC_LOG_STATUS)`` |
| |
| Arguments |
| ========= |
| |
| ``fd`` |
| File descriptor returned by :c:func:`open()`. |
| |
| Description |
| =========== |
| |
| As the video/audio devices become more complicated it becomes harder to |
| debug problems. When this ioctl is called the driver will output the |
| current device status to the kernel log. This is particular useful when |
| dealing with problems like no sound, no video and incorrectly tuned |
| channels. Also many modern devices autodetect video and audio standards |
| and this ioctl will report what the device thinks what the standard is. |
| Mismatches may give an indication where the problem is. |
| |
| This ioctl is optional and not all drivers support it. It was introduced |
| in Linux 2.6.15. |
| |
| Return Value |
| ============ |
| |
| On success 0 is returned, on error -1 and the ``errno`` variable is set |
| appropriately. The generic error codes are described at the |
| :ref:`Generic Error Codes <gen-errors>` chapter. |
