hi all!
thank you for that great piece of software!
i updated from version 1 to version 2 of my “never touch a running system” audio-box.
i used a raspberry 2 with 8gb sd, volumio 2 and a hifiberry dac+.
but after the first start audio-output seems not to work.
the audiocard may detect correct:
[code]…
cat /boot/config.txt
dtoverlay=hifiberry-dacplus
[/code]
…but no sound is hearing.
i consider dmesg to got some kernel feedback and found that:
> dmesg
...
[ 3.296854] vc_vchi_sm_init: failed to open VCHI service (-1)
[ 3.296855] [vc_sm_connected_init]: failed to initialize shared memory service
...
[ 7.388571] snd-rpi-hifiberry-dacplus soc:sound: ASoC: CPU DAI (null) not registered
[ 7.398322] snd-rpi-hifiberry-dacplus soc:sound: snd_soc_register_card() failed: -517
[ 7.410431] snd-rpi-hifiberry-dacplus soc:sound: ASoC: CODEC DAI pcm512x-hifi not registered
[ 7.420783] snd-rpi-hifiberry-dacplus soc:sound: snd_soc_register_card() failed: -517
[ 7.723725] snd-rpi-hifiberry-dacplus soc:sound: pcm512x-hifi <-> 3f203000.i2s mapping ok
...i know that kind of error and do a bit internet-search to got a confirmation about that:
Source: https://github.com/raspberrypi/firmware/issues/428
it seems that the needfull functions will not be loaded if the gpu-mem is less than 32gb.
if i changed the config, sound-output works very well!
[code]> cat/boot/config.txt
gpu_mem=16
gpu_mem=32
[/code]
i did some search about this but bug didn’t find anything. hope i do not double-reporte it 
thank you for support & development!