Created attachment 90786 [details]
Kernel log with monitor attached to display port

I own an ASUS Nvidia GTX 660 card. If I connect a monitor to the HDMI
connector, sound works. If I connect a monitor to the display port connector,
sound does not work. In the latter case, all /proc/asound/NVidia/eld* show the
output

monitor_present         0
eld_valid               0

If I connect a monitor to the HDMI port, "monitor_present" shows "1".

Kernel: 3.12.5 (Gentoo)
Dmesg for the display port case (failure case): See attachment