I have a AV Receiver plugged into my Radeon HD5670 via HDMI, using ATI HDMI audio. It used to work fairly well on Windows 7 (and Linux too). But I am having troubles with Windows 8. Windows 8 64 bit. Driver is "AMD High Definition Audio Device", version 188.8.131.5209 (also tried the beta 184.108.40.20611), from 2012-12-21. (the graphics driver from the package is version 220.127.116.11).
My receiver (Onkyo TX-SR309) has a variety of regimes of signal processing, which it plugs automatically. On Windows 7 once HDMI was connected and the first audio signal received - it connected the HDMI+PCM mode, and stayed that way until turning off one of the devices implicated. On Windows 8 however, it turns off the HDMI+PCM mode soon after playback stops. I know it's software related since Foobar2000 turns off the HDMI+PCM mode even between tracks, while in AIMP3 I can switch tracks and even pause for a short while, without this switch happening.
The reason this is frustrating is because it takes about 2-3 seconds for the switch of audio modes to take place on the receiver. It's so bad that I can't even perform room correction since the sound plays during the receiver mode initialization.
I've had no business with handling audio streams in software and drivers, so I can only speculate that my receiver holds the HDMI+PCM mode as long as the audio driver has an open data stream with the receiver.
So I am asking: how do I make the link persistent, so it won't disappear after I stop playback of any audio stream.