Observation: Audacity not see cs46xx devices (only onboard USB sound & vup/ downmix devices).
But ALSA tools & Ardour see, and they are able to capture/ output sound.
The error messg a got when starting audacity was something like in pa_alsa_linux.c function “set_period_size_near(…”. (cs46xx supports period_size 512 only at max).
After weeks over weeks of troubleshooting I got the impression that the underlying portaudio lib may be blamed for this error. So, I began swapping the portaudio lib against older versions a several times.
These are my findings, all with Audacity from Debian Buster repository v2.2.2:
portaudio stock version from Debian Buster => not works, Audacity not see devices of cs46xx (orig ticket issue)
portaudio2_19+svn2014XXX (in Debian Jessie?) => Nope, same as above
portaudio2_19+svn2011XXX (in Debian Wheezy/ Ubuntu?) => Ok, Audacity can record & play!
Seems, something has broken on the way from portaudio svn2011XXX up to => 2014XXX…
Hope, this helps any user in dispair as I was. And maybe, you developers manage to correct this issue in future versions of portaudio.
Thank you for your attention, and keep up your good work!