Yesterday, I resolved a problem of a soundcard with Linux. That PC had a Realtek Integrated soundcard (ICH5) and the rear output didn’t work, to listen audio, it was possible only using headphone in the front microphone.

Here there is the model, using lspci:

00:1f.5 Multimedia audio controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) AC’97 Audio Controller (rev 02)

The solution is quite easy. Time ago I wrote a similar document about my soundcard. The problem is the hardware implementation of soundcard is based only on a driver (that you can install only with windows) and in Linux no information are provided to use correct soundcard’s settings.
So, as I wrote, is necessary to give when module (in this case snd_8x0) is probed, a options. To see which options, you should install source code or documentation of kernel and you find in Documentation/sound/alsa/ALSA-Documentation.txt file.

After found the correct module, you should edit /etc/modprobe.conf as follow:

options snd-intel8x0 ac97_clock=0 ac97_quirk=inv_eapd

The more important option, in this case, is ac97_quirk, and for my soundcard is set to “inv_eapd”, there are many other options, and, if you are not sure, is better to try all. You can find in the “ac97_quirk” section in ALSA-Documentation.txt file.

After this, (this is a particular settings of my soundcard) I choose 4 channels and shared computation (instead indipendent) and it work with rear output.

I’m sorry if this article is not explain so good. I know but I wrote fast. If you find mistakes, tell me by comments.