So due to reasons I won't get into too much here (my AVR is old and doesn't support newer formats) I have to output my [HT]PC to my AVR via a second HDMI. Therefore I have to have one HDMI cable go from my main GPU (RX 5700) to the TV directly and then another running a 1080p signal to my AVR for audio. Due to AMDs continued insistence
to run the VRAM clock higher than single-monitor idle, with "dual "monitors", I instead use my Intel iGPU (i5-8400/UHD 630) output for the audio. This avoids 2x idle power consumption and increased heat on the GPU. The "power cost" of the iGPU is basically nothing, a couple watts, so much better than running the dGPU in "dual monitor".
The one minor hitch is that sometimes, the AVR doesn't properly decode the signal--it says it's receiving and the PC says it's sending to that output device but the output is muted. With my previous HTPC (Haswell based so it had an HD 4600 iGPU) all I had to do when this "mismatch" happened was power cycle the AVR and then it would work fine.
The same is true now, but the process is not
automatic. The Coffee Lake iGPU driver doesn't detect the AVR after you turn it back on, and so audio switches to TV audio in Windows. As soon as I open the Intel Graphics control panel though, it then detects the AVR and it's available as an audio device and it takes over by default. However I still have to open the Intel application in order for it to detect the "monitor" (the AVR).
I looked everywhere in the Intel control panel but can't find a thing about auto-detection or anything similar. Is there a registry setting or some other way to make this work like it did with the older iGPU on the Haswell CPU? Or am I stuck power cycling the AVR and
opening the Intel panel to fix this every time?