So, I'm not really happy with this current build.
Is it more flexible than the Amazon OS? Yes, of course. But is it really "better"? No. Absolutely not.
1. I see tons of IOWAIT for no real reason and
it ends up as lag everywhere. It's not the device. It's something in the kernel which is causing it. End result: the device doesn't feel snappy at all. :/ You go to unlock the screen and it sits for a good second or 2. Open an app.. it sits for a second or 2, etc. I'm guessing that there's some driver in the kernel which is hard looping or something.
2.
I hate the current sensor setup. It's all proprietary Amazon files and the gyroscope is backwards causing more issues. To fix it, I need to be able to compile my own sources for the sensors. Which means using open source IIO-based Invensense drivers which I found in the Nexus 10 kernel. So thats: backport them to 3.0 kernel or move the entire device over to 3.4 kernel and use them there. Either way, new sensor driver for the kernel and then I can use the IIO-based Invensense sensor source from AOSP (with a little re-work).
3.
Sound issues are still pretty big at the moment. Background audio clocking issues, odd audio buffer setup or more audio android layer debugging are all needed. And it'll probably be a good week or 2 of more dedicated debugging on the audio system to really root out the "whys" and "hows" of our current audio issues.
4.
Power driver is lacking a ton of features in my opinion. It does exactly what it's supposed to and nothing else. It detects a power source and turns on charging. We're missing the entire OTG implementation.
5.
Camera quality is currently: terrible. I know it's a very cheesy camera built for video chat basically, but it can be better.
How to solve these issues in the best way possible? Still mulling over my options. The 3.4 kernel I'm working on for the 1st gen Kindle Fire is nearly done. So that's a viable option. But, there's a huge amount of back tracking and device setup before it even gets back to the current state. And if we do move to the 3.4 kernel: the camera is instantly broken until I can completely re-write the driver using V4L2 interface in Android -- so that becomes additional work in #5.
All in all, I'm very frustrated at the amount of work that I'm putting into the Fire HD's and the amount of progress they're showing. :/
So I'm venting.
I'll post later on my any direction changes I'm taking.