I did both tests because I wasn't sure whether it was necessary to test the unload code snippet or not. As expected, without removing the parent PCI device, an oops. Once I manually removed it, followed by the unload code snippet, all unloaded well. I've mv'd away asound.state. Quick question before I reboot, should I reload with the Fedora alsa.cfg before the reboot? (Obviously I am unclear on how the sound stuff works ... :)