Following up on my earlier posting on the AD2000BX/AD1989B SPDIF support being broken, I figured out the required fixes, and they are waiting in the sound-2.6 kernel tree for the next merge window
Code fixed now, no specs available yet See my patches here.Edit 2008/09/05:
A private source that I inquired of indicates that the AD2000B part was only a special run of the AD1989B part. There shouldn't be any functional differences. On the side of a spec sheet, the AD1989B specs should be available "shortly" from Analog Devices.Original posting:
So in more details to follow, I picked up hardware for a new workstation to replace my G5. The only part of the hardware that isn't working yet, is the digital audio (SPDIF/Toslink) output. My motherboard is an Asus P5Q-Premium, and the specifications claim to have "ADI® AD2000B 8-Channel High Definition Audio CODEC" as the audio chip. This chip is apparently the successor to the AD1988B chip. The analog audio part works fine, just that I use optical to overcome an interference issue on the run between my computers and my actual working area of my desk (with a small digital decoder and stereo speakers).
Digging around in the ALSA drivers, it just seems I need to find a different set of controls to toggle the digital lines to be outputs or enabled - and that this data would be in the public datasheet, just like previous versions of the chip. I submitted a technical request to Asus a few days ago, with no response yet. I also contacted Analog Devices directly. Their customer support referred me to their application engineers, whom I phoned, and they then proceeded to deny the existence of the chip, and I quote: "It's not in my system, we don't manufacture it." That's really interesting, because I've got it on my motherboard!
Either the divisions of Analog Devices aren't talking, or Asus is using chips from a 3rd party that's ripping off Analog Device's trademark amongst other things.
Here's the text off the chip:
AD2000BX 14??793.1 #0816 0.3 SINGAPORE
I tried to take a photo, but it's really annoying and hard to read, without dis-assembling my machine, which I'd prefer not to do at this point.
However, I did find another photo on the web, of the same area from a review of the motherboard. The Analog Devices logo is also clearly visible after the 'BX' portion of the text. From the photo I could make out:
AD2000BX 1383055.1 #0808 0.2 SINGAPORE
If I had to make a guess about it, the chip is AD2000BX, the second line is the serial number, the third is the year and week of manufacturer, plus the revision of the chip, and the last line is the manufacture location.
If you're from Asus or Analog Devices, and you're reading this, where's the datasheet for the chip? Is it a real ADI part? I simply want the public datasheet like the rest of models so that I can fix digital audio output in Linux myself, and contribute it back to the ALSA project.
P.S. The upstream ALSA bug is here. There's no downstream Gentoo bug.