There is finally good news from an Intel developer when it comes to the HDMI audio passthrough problems that we’ve been seeing with the Intel Apollo Lake and Kaby Lake based devices that utilize an LSPCon to convert the DP 1.2 signal to HDMI 2.0 signal. Previously DTS-X, DTS-HD and Dolby TrueHD audio formats were not working at all under Linux, even if they were ok under Windows.
Why this was important? Well, for example, it was basically impossible to hear any Dolby Atmos content on LibreELEC or any other Linux distribution. Until this day I have not really been able to recommend the Apollo Lake devices for HTPC usage.
In any case, there’s a suggested kernel patch in this bug report. There are already reports of the patch actually fixing the passthrough issue so it sounds very promising. There will probably be a LibreELEC test build with this patch available tomorrow. I’ll definitely try that one out and report my findings as soon as I’ve tested this.
So as a reminder, the HDMI (LSPCon) firmware will needs to be updated if you haven’t done that yet. The latest update from March 2017 is 1.66 and available here. I did write an article describing the update procedure earlier this year.