[BUG] HDA Intel PCH, HDMI , HDA Intel PCH, ALC886 Digital, no IEC958 / HDMI output/passthrough to AVR

ALSA versions 1.0.25...current

Kernel Driver versions 3.12.40...6.x

Hardware:

DFI Mainboard MB330-CRM

https://www.dfi.com/de/product/index/273#specification

Reproducible Always

Steps to reproduce and full report:

https://www-vdr--portal-de.translate.goog/forum/index.php?thread/136519-gel%C3%B6st-xineliboutput-config-f%C3%BCr-dd-passthrough-zu-avr-und-5-1-surround-headset/&postID=1375883&_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=de&_x_tr_pto=wapp#post1375883

Output of alsa-info.sh is here http://alsa-project.org/db/?f=fc4734deddd9a92331692bf94b15cf84b7722cd4

Software crosscheck with CM106 USB Soundbox iec958: works OK.

Where to start in the drivers source code to fix it?

y tom