Comment # 3 on bug 1039441 from Takashi Iwai

(In reply to Michal Suchanek from comment #2)
> I tried some debugging guide after some fiddling I got into a state when
> pulseaudio was still not working and aplay was failing due to device busy.

In that case, you can run like
  pasuspender -- aplay -Dsysdefault foo.wav

If this still gives EBUSY, it means something else is blocking.  Check via
fuser -v /dev/snd/*.

> Unfortunately, I already got the system into working state so I cannot
> recheck I had the correct device and whatnot.
> 
> [   99.893876] snd_hda_codec_idt hdaudioC0D0: autoconfig for 92HD91BXX:
> line_outs=1 (0xd/0x0/0x0/0x0/0x0) type:speaker
....

Could you give alsa-info.sh output?