summaryrefslogtreecommitdiffstats
path: root/Documentation/userspace-api/media/v4l/vidioc-log-status.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-log-status.rst')
-rw-r--r--Documentation/userspace-api/media/v4l/vidioc-log-status.rst47
1 files changed, 47 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-log-status.rst b/Documentation/userspace-api/media/v4l/vidioc-log-status.rst
new file mode 100644
index 000000000..c218747be
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/vidioc-log-status.rst
@@ -0,0 +1,47 @@
+.. 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.