Comment 299 for bug 1166529

Just found this thread, hopefully I'm not breaking any rules by posting on a few different ones. I've got full functionality on my Sound Blaster Z working now, and have the firmware and patch file uploaded here:
https://drive.google.com/drive/folders/1r-X8g6It5AO7SwgJc1JQfJ8KCOyqrr_d
You'll have to compile your own kernel and put the ctefx-sbz.bin firmware in your /lib/firmware folder. It's currently only tested on my Sound Blaster Z, which has an implementation ID of 0023. You can get this by sending the hda-verb 0xF20 to node 0x01. Hopefully it works for someone else.