Roaming the forums i note these lines :
Playback open error: -16,Device or resource busy
Could it be that hifiberry is occupied with a parasitic process of some sort (the “busy” stuff) ?
Is so, how can i control, seek and kill it ?
It seems some users had the problem (with not exactly same card but meh…) and solved it by some commandlines i’m not sure i can use for my case : No Alsa/jack from zynthian image but Hifiberry Amp+ plays from hifiberry image
It refers to “jack”, this little guy is present many times in my mystery case… could it be the culprit ?