18c2ecf20Sopenharmony_ci.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 28c2ecf20Sopenharmony_ci.. c:namespace:: V4L 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ci.. _VIDIOC_LOG_STATUS: 58c2ecf20Sopenharmony_ci 68c2ecf20Sopenharmony_ci*********************** 78c2ecf20Sopenharmony_ciioctl VIDIOC_LOG_STATUS 88c2ecf20Sopenharmony_ci*********************** 98c2ecf20Sopenharmony_ci 108c2ecf20Sopenharmony_ciName 118c2ecf20Sopenharmony_ci==== 128c2ecf20Sopenharmony_ci 138c2ecf20Sopenharmony_ciVIDIOC_LOG_STATUS - Log driver status information 148c2ecf20Sopenharmony_ci 158c2ecf20Sopenharmony_ciSynopsis 168c2ecf20Sopenharmony_ci======== 178c2ecf20Sopenharmony_ci 188c2ecf20Sopenharmony_ci.. c:macro:: VIDIOC_LOG_STATUS 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci``int ioctl(int fd, VIDIOC_LOG_STATUS)`` 218c2ecf20Sopenharmony_ci 228c2ecf20Sopenharmony_ciArguments 238c2ecf20Sopenharmony_ci========= 248c2ecf20Sopenharmony_ci 258c2ecf20Sopenharmony_ci``fd`` 268c2ecf20Sopenharmony_ci File descriptor returned by :c:func:`open()`. 278c2ecf20Sopenharmony_ci 288c2ecf20Sopenharmony_ciDescription 298c2ecf20Sopenharmony_ci=========== 308c2ecf20Sopenharmony_ci 318c2ecf20Sopenharmony_ciAs the video/audio devices become more complicated it becomes harder to 328c2ecf20Sopenharmony_cidebug problems. When this ioctl is called the driver will output the 338c2ecf20Sopenharmony_cicurrent device status to the kernel log. This is particular useful when 348c2ecf20Sopenharmony_cidealing with problems like no sound, no video and incorrectly tuned 358c2ecf20Sopenharmony_cichannels. Also many modern devices autodetect video and audio standards 368c2ecf20Sopenharmony_ciand this ioctl will report what the device thinks what the standard is. 378c2ecf20Sopenharmony_ciMismatches may give an indication where the problem is. 388c2ecf20Sopenharmony_ci 398c2ecf20Sopenharmony_ciThis ioctl is optional and not all drivers support it. It was introduced 408c2ecf20Sopenharmony_ciin Linux 2.6.15. 418c2ecf20Sopenharmony_ci 428c2ecf20Sopenharmony_ciReturn Value 438c2ecf20Sopenharmony_ci============ 448c2ecf20Sopenharmony_ci 458c2ecf20Sopenharmony_ciOn success 0 is returned, on error -1 and the ``errno`` variable is set 468c2ecf20Sopenharmony_ciappropriately. The generic error codes are described at the 478c2ecf20Sopenharmony_ci:ref:`Generic Error Codes <gen-errors>` chapter. 48