I spent last hours torture testing my device and trying to reproduce deaf CEC with another setup (Onkyo AVR + TV Samsung UHD).
- tested RAM and CPU for 12h (memtester + prime95 under ubuntu 16.04): no errors detected
- some eMMC tests - also OK
- tried very hard to reproduce deaf CEC with Samsung TV with my device: no success
- I did managed to have "Auto switch back" with samsung TV
on LibreELEC-Odroid_C2.aarch64-7.0.1.DTS-HD.img. Log: http://sprunge.us/DBMY
(your fix for "Sony TV" works here also - no problem on LibreELEC-Odroid_C2.aarch64-7.0.1.HDMI-CECv1.tar)
- I cannot switch to UHD kodi or play UHD samples. I get "unknown input" (LibreELEC-Odroid_C2.aarch64-7.0.1.DTS-HD.img). Dmesg log from playback http://sprunge.us/LHfI
- I did managed to switch Kodi to UHD and playback UHD samples on LibreELEC-Odroid_C2.aarch64-7.0.1.HDMI-CECv1.tar... no idea what's the difference
- tried UHD 29.970 sample - kodi switched to UHD 50p.. (24p sample correctly switched to 24p). Log: http://sprunge.us/adMV
- 30 fps sample - the same as above
I also noticed that C2 is much cooler under Ubuntu than LE..
Checked device with thermal probe - the radiator is about 5 centigrades cooler than temp reported. So i think the temperatures are reported correctly. The memory chips on the other side of PCB are also quite hot - about 65 - 70 degrees C with idle Kodi (C2 inside a case).