Hi, i recently requested to reopen https://bugs.archlinux.org/task/31255
but thought i should have mailed here first.
The alsa powersave patch applied to 3.5.3 didnt fix the issue for me. I
set CONFIG_SND_HDA_POWER_SAVE_DEFAULT=0 to nonzero and the issue is
resolved. Perhaps this is just localized to my hardware i dont know but
if anyone else is still experiencing 100% usage this is what fixed it