I am using Radeon HD 4870 connected via DVI to the monitor and via HDMI to the a TV.
When I want to watch a movie, I use the HDMI audio device to send the audio to the TV. The device is always properly displayed by 'asound -l':
card 2: HDMI [HDA ATI HDMI], device 3: HDMI 0 [HDMI 0]
Subdevice #0: subdevice #0
The problem is that there is random chance that the audio device will work or not, that is probably defined upon system start-up or at first usage. If it worked once since last boot, it will work until system shutdown. If not, it will not work until I reboot the machine. Actually it seems that is necessary a full power down for it to have chance of working on the next boot-up (maybe some uncleaned volatile memory?).
The other audio devices are unaffected.
Please attach dmesg output.