Under gnome control panel, all seems ok: under sound preferences, sound output is configured to use HDMI channel.
I am using nvidia drivers from elrepo.org (nvidia-x11-drv-290.10 and kmod-nvidia-290.10). Somebody knows where can I find some doc to resolve this? Any idea?
I recall doing this on Fedora 14 for my HTPC so it should be similar or at least point you in the right direction. I wrote something for it (GeForce 210) here:
http://taiter.com/techlog/2010/07/nvidia-gt210---hdmi-audio.html
I remember having to update the alsa-driver package to something newer than what was default via ATrpms repo. I believe you need version 1.0.23 or newer for it to work (version can be checked by looking at /proc/asound/version).
Then I had to go into alsamixer and unmute the line.
Tait