I think the reason why they used PCON is space constraints of the NUC motherboard.
mDP + a native HDMI would require routing separate traces from SoC to HDMI and mDP ports.
mDP + HDMI with PCON does not require extra traces for HDMI, probably DisplayPort MST function is used.
we know hardware is capable as since Gemnini Lake Intel supports HDR in Windows
so its just Linux which cant do it properly with DP to HDMI. Maybe the patches used for earlier NUCs need to be updated.
In other news......
Ethernet and WiFi also not working in Libreelec on NUC11PAH. I am using a USB Wifi dongle which needs to be unplugged and plugged back in after a reboot.
I think I can fix Ethernet.
Your vainfo output doesn't look right. Looks like Tiger Lake require Intel's media-driver which I did not include in my build.
I will post another build in an hour or so. Please re-test HDR and Ethernet.
we know hardware is capable as since Gemnini Lake Intel supports HDR in Windows
so its just Linux which cant do it properly with DP to HDMI. Maybe the patches used for earlier NUCs need to be updated.
Gemini Lake has native HDMI 2.0a and no LSPCON / PCON
smp does your builds use kernel version 5.9+?
5.10.16
Both Ethernet and WiFi now working
Plays SDR video fine
Playing HDR video crashes libreelec and TV displays 'No Signal'. NUC remains powered and on. The only way to recover is to pull the power cord.
Running 'vainfo' results:
LibreELEC:~ # vainfo
libva info: VA-API version 1.10.0
libva info: Trying to open /usr/lib/dri/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_10
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.10 (libva 2.10.0)
vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 20.4.5 (d8b557f424)
vainfo: Supported profile and entrypoints
VAProfileNone : VAEntrypointVideoProc
VAProfileNone : VAEntrypointStats
VAProfileMPEG2Simple : VAEntrypointVLD
VAProfileMPEG2Main : VAEntrypointVLD
VAProfileH264Main : VAEntrypointVLD
VAProfileH264Main : VAEntrypointEncSliceLP
VAProfileH264High : VAEntrypointVLD
VAProfileH264High : VAEntrypointEncSliceLP
VAProfileJPEGBaseline : VAEntrypointVLD
VAProfileJPEGBaseline : VAEntrypointEncPicture
VAProfileH264ConstrainedBaseline: VAEntrypointVLD
VAProfileH264ConstrainedBaseline: VAEntrypointEncSliceLP
VAProfileVP8Version0_3 : VAEntrypointVLD
VAProfileHEVCMain : VAEntrypointVLD
VAProfileHEVCMain : VAEntrypointEncSliceLP
VAProfileHEVCMain10 : VAEntrypointVLD
VAProfileHEVCMain10 : VAEntrypointEncSliceLP
VAProfileVP9Profile0 : VAEntrypointVLD
VAProfileVP9Profile1 : VAEntrypointVLD
VAProfileVP9Profile2 : VAEntrypointVLD
VAProfileVP9Profile3 : VAEntrypointVLD
VAProfileHEVCMain12 : VAEntrypointVLD
VAProfileHEVCMain422_10 : VAEntrypointVLD
VAProfileHEVCMain422_12 : VAEntrypointVLD
VAProfileHEVCMain444 : VAEntrypointVLD
VAProfileHEVCMain444 : VAEntrypointEncSliceLP
VAProfileHEVCMain444_10 : VAEntrypointVLD
VAProfileHEVCMain444_10 : VAEntrypointEncSliceLP
VAProfileHEVCMain444_12 : VAEntrypointVLD
VAProfileHEVCSccMain : VAEntrypointVLD
VAProfileHEVCSccMain : VAEntrypointEncSliceLP
VAProfileHEVCSccMain10 : VAEntrypointVLD
VAProfileHEVCSccMain10 : VAEntrypointEncSliceLP
VAProfileHEVCSccMain444 : VAEntrypointVLD
VAProfileHEVCSccMain444 : VAEntrypointEncSliceLP
VAProfileAV1Profile0 : VAEntrypointVLD
VAProfileHEVCSccMain444_10 : VAEntrypointVLD
VAProfileHEVCSccMain444_10 : VAEntrypointEncSliceLP
Playing HDR video crashes libreelec and TV displays 'No Signal'
That's some progress at least 
I will now do another build with some changes.
Confirmed HDR is working!
Just to clarify and remove confusion is this specifically for the Intel Iris X Graphics or will it also work for the Intel UHD Graphics in the i3 model.
Confirmed HDR is working!
That's great news!
But keep in mind that HDR code is early and has some bugs.
For example, HDR mode sometimes does not switch off when you switch from HDR to SDR video.
Another bug I noticed - if you switch the TV off and then on again - HDR may not work anymore and Kodi must be restarted to fix this.
should it also work on nuc 11 Pro?
