I have a Jetway J9F2 Extreme motherboard as shown here: http://www.jetway.com.tw/jetway/system/productshow2.asp?id=404&proname=J9F2-Extreme I am unable to get the hdmi audio out to work at all. I know the hardware is capable of hdmi audio out because this works correctly under windows. The analog audio out works just fine. From my understanding this board has a Intel High Definition Audio sound device, with a Realtek ALC888 codec. I would be happy to spend time providing any information that would be helpful in debugging this.
I have had a chance to look at this a bit more and I believe I was incorrect about the audio codec chip. The ALC888 chip exists on the board, however I believe it is only responsible for analog out and digital/spdif out. I believe the HDMI audio is controlled, in hardware, by a Chrontel CH7315. http://www.chrontel.com/products/7315.htm
This bug has been fixed with the latest kernel update.