Power management/Soundcard

This article describes the setup of power management of sound devices.

Power-saving mode
The Intel HDA driver has a power-saving mode to suspend the soundcard after some time of inactivity.

Kernel
If you have an AC97 soundcard, you need to activate the following kernel options:

If you have a HDA soundcard, you need to activate the following kernel options:

Runtime tuning
You can tune the driver in the sysfs filesystem under
 * The knob controls, if power-saving mode is enabled. It's preset by the kernel option ... power-saving ....
 * The knob sets the time-out in seconds. It's preset by the kernel option Default time-out ...

pm-utils
pm-utils contains a script to enable the power-saving mode when on battery and disable when on AC. It overrides the default values of the kernel.

If you use pm-utils, but don't want this kind of regulation, disable the script:

PulseAudio
If you have an Intel HDA soundcard and use PulseAudio, you probably want the following kernel option to improve power-saving:

Troubleshooting
If you hear a unwanted click sound, when the power-saving mode enables, disable the power-saving mode in the kernel.