Looking to see, illustrated, how the kernel does access some PCI soundcard. E.g., device I/O, device registers, function calls (including calls to DMA, data not required - can guess it from sources). Want to get a log, <...read it, write some script to make a Graphviz chart>,
I can setup virtual machine for testing, had pointed out several things to look upon in ALSA code, but still have no idea how to get the whole stuff tracked in realtime..
The ideal debug mode for me is to enter debugging mode, load modules, call aplay to send data to sound card, unload modules, exit debugging mode, dump debugging log to file.. Any kind of recommendations would be fine.