Originally Posted by Stephen Warren
For future reference for anyone reading this thread:
The standard kernel ALSA drivers handle the audio portion of NVIDIA GPUs and chipset.
The NVIDIA binary driver is required to pass some of the monitor information to the audio driver.
X must be running for audio to work.
The latest ALSA drivers and library have a couple issues that prevent all this working in some cases. You'll need a few patches from ALSA git to solve this.
a) For all GPUs, and the MCP89 chipset: You need a fix for the PresenceDetect issue:
Is there a fix for MCP79 and MCP79A chipsets? The latest driver version 260.19.06 broke the HDMI audio on the Ion (no mode /dev/audio). Attached is the log file.