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kernel/linux-rt-4.4.41/Documentation/DocBook/media/v4l/vidioc-log-status.xml 1.24 KB
5113f6f70   김현기   kernel add
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  <refentry id="vidioc-log-status">
    <refmeta>
      <refentrytitle>ioctl VIDIOC_LOG_STATUS</refentrytitle>
      &manvol;
    </refmeta>
  
    <refnamediv>
      <refname>VIDIOC_LOG_STATUS</refname>
      <refpurpose>Log driver status information</refpurpose>
    </refnamediv>
  
    <refsynopsisdiv>
      <funcsynopsis>
        <funcprototype>
  	<funcdef>int <function>ioctl</function></funcdef>
  	<paramdef>int <parameter>fd</parameter></paramdef>
  	<paramdef>int <parameter>request</parameter></paramdef>
        </funcprototype>
      </funcsynopsis>
    </refsynopsisdiv>
  
    <refsect1>
      <title>Description</title>
  
      <para>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.</para>
  
      <para>This ioctl is optional and not all drivers support it. It
  was introduced in Linux 2.6.15.</para>
    </refsect1>
  
    <refsect1>
      &return-value;
    </refsect1>
  </refentry>