play after long silcence produces garbage

```
What steps will reproduce the problem?
1. Play some Album.
2. After the Album finished to nothing for the next few hours (over night).
3. Start playing some music.

What is the expected output? What do you see instead?
Music is expected. Instead there is silcence, after about 30 s there comes
computer garbage sound (nothing like music).

What version of the product are you using? On what operating system?
I'm using git latest (8f0e4f2aa0f7) on TL-MR3020 running OpenWrt Attitude
Adjustment.

Please provide any additional information below.
If I first power off the device (via LMS) and then start playing music
everything is fine. So I guess power off does some kind of Alsa disconnect and
would assume an Alsa Disconnect after playback is finished would fix the
problem.

Btw: There is no spectacular info in the log, unfortunately...
```

Original issue reported on code.google.com by `tutm...@gmail.com` on 18 Jun 2013 at 5:53