2010/4/30 pl bossart bossart.nospam@gmail.com
Howdy, When PulseAudio is used and all PCM is routed through PulseAudio (Fedora, Meego, etc), the notion of ALSA periods isn't very useful. PulseAudio uses a timer to refill buffers and the period interrupts are not used at all.
So why not disable them entirely to reduce the number of wakeups? This is possible with a number of existing DMA controllers. The simple patch attached shows a proof-of-concept on HDAudio, it's been working for 5 hours on my Fedora12 laptop without any glitches and powertop does show _zero_ wakeups from the HDAudio controller (except on startup). I am told by my colleagues working in Windows environments that this is what's done on Vista/Windows7 btw. This isn't to say Windows is great but that artificial generation of not-needed interrupts is avoidable.
Do your test need the patch which you have posted to pulseaudio developer mailing list
http://thread.gmane.org/gmane.comp.audio.pulseaudio.general/6671
it seem that fix should be in driver side if it is hardware specific