Wrote it already in reply to your PM, but... :P

I don't really think that editing AppleHDA is what fixed popping. Did you have the problem before? If not - patching AppleHDA isn't the fix. The only way to fix it is to edit IOAudioFamily kext or add a small code to DSDT (works only when HP isn't connected, I still have to figure out how to make it work... although I don't have a problem with popping myself either, ALC662 is a bizarre audio codec - some people even claim to have this kind of popping under Windows o.O), where you can find code regarding PowerState. It's a problem with audio going to 'sleep' after certain amount of time without playing music etc. and it's not connected to AppleHDA itself but IOAudioFamily. At least from what I've seen in it's source code.

+ Your AppleHDA patch is a bit messy. You've should removed some parts of Layouts that are not in use. What's more - your pinconfigs aren't really in Mac OS X style - it works but it wouldn't work in some cases. In general - when creating LegacyHDA/editing AppleHDA - you shouldn't use rough pinconfig from Ubuntu but edit it in some parts. Feel free to look at my LegacyHDA from the tutorial, it may give you the idea of what I mean. Don't take it offensive, I simply know how hard it's to get into using AppleHDA to enable audio, since there aren't many sources of knowledge unfortunately and I want to help you in understanding it as I've spend a long time testing all this stuff.

@aliquot
When I have some free time I will send you a PM! Thanks a lot!