If you have an intel sound card and you are concerned about battery life, probably you have seen this in the powetop output…
100.0% Device Audio codec hwC0D0:
Conexant
After much duck-duck-ing around I found this enlightening comment on the lesswatt mailing list. It turns out that to enable power management on this device, the device must be open first. Something like
echo -n | aplay
in your rc.local script should do the trick.
hopefully this will give me few more minutes of battery time. Still no clue for the other device :
100.0% Device Audio codec hwC0D3:
Intel
This page has plenty of good tips, most of them already integrated in the laptop-mode package in debian…
I added a couple of lines to my /etc/sysfs.conf file :
module/snd_hda_intel/parameters/power_save=1
module/snd_hda_intel/parameters/power_save_controller=Y
but the Audio codec hwC0D3: Intel is still there hanging with 100% :(