The reliability of it's multi DAC / playback channels is
not that good. Enabling vchans make the bug more visible
since playback allocation will look for possible free
hardware channels first (i.e: the next DAC, the very first
has been consumed by vchan mixer) which in this case has
been proven faulty.
Reported / Tested by: Sascha Klauder
MFC after: 3 days