title: running adb devices showing unauthorized device?
body: <p>I have connected some android devices to a Linux host. and when I run </p>
  
  <pre><code>adb devices
  </code></pre>
  
  <p>it will show unauthorized device. I fix this problem by </p>
  
  <pre><code>adb kill-server
  sudo adb start-server
  </code></pre>
  
  <p>but every time the host restarts it will again show device unauthorized. please can someone explain how to fix this problem permanently.</p>
  
  <p>The device is connected to the host through the USB cable.</p>