title: “error: closed” displayed when trying to connect to Android device via adb through TCP
body: <p>I'm building up Android system on a ARMv7 dev-board. For some reason I would like to use "adb shell" to manipulate the system from my PC. The dev-board and the PC are connected via Ethernet since the Android system use NFS sever as its root file system. Here's what I've tried (I have root access on the Android device):</p>
  
  <p>On the Android device (accessed via serial port with putty):</p>
  
  <pre><code>android@ubuntu:~$ setprop service.adb.tcp.port 5555
  android@ubuntu:~$ stop adbd
  android@ubuntu:~$ start adbd
  </code></pre>
  
  <p>On the Ubuntu host: </p>
  
  <pre><code>android@ubuntu:~$ adb connect 192.168.0.85:5555
  connected to 192.168.0.85:5555
  android@ubuntu:~$ adb shell
  error: closed
  android@ubuntu:~$ adb devices
  List of devices attached
  192.168.0.85:5555       device
  </code></pre>
  
  <p>As the message shows, the connection via adb seems successful (connected to ...), however I can't "adb shell" to it. The most weird is that I can still see the device attached via "adb devices".</p>
  
  <p>I tried to kill adb server and restart it, but it doesn't work either.</p>