Hi Liam, Mark, Colin, and all, I study the codes in pulseaudio and alsa ucm patch recently, and create a page of my study result. I appreciate your feedback. The page is at https://wiki.linaro.org/WorkingGroups/Middleware/Multimedia/Specs/1111/Audio.... Also if needed, I'm glad to contribute to the integration of alsa ucm in pulseaudio. Thank you.