title: v4l2 kernel space debugging
body: <p>Is there any default mechanism to enable debugging the v4l2 drivers.
  Basically I want to check something like dynamic debugging by setting in /d.
  Compile time flags in make file also fine.</p>
  
  <p>Currently, I had set as below, however not getting much information.</p>
  
  <pre><code>echo -n 0xFFFF&gt;/sys/module/videobuf2_core/parameters/debug
  </code></pre>
  
  <p>Can anybody help me to get verbose v4l2 logs?</p>