R9 390 dual monitor issue in monterey

[wwatu]

So, while being stuck on High Sierra for ages with GTX960, I finally decided to get an AMD GPU, so got my hands on Asus R9 390 DC-2, with that, decided to change from Clover to OC, upgraded do Monterey, and everything is working besides for dual monitor, initially I had my main monitor connected to DVI and TV via HDMI and dual screens seemed to work, but since this GPU's output priority is different, I bough a DP to HDMI adapter, which also fixed no audio over DVI with the new setup, and my main monitor now gets boot screen, only to find the issue that when I plug in the TV via HDMI, both screens turn black, this seems to be very common issue with even newer cards, while searching I didn't really find any other fix anywhere than to put mac to sleep, plug in hdmi and wake up, this seems to be only fix.

So my question being, is there any real fix to this? Whatevergreen seems to assing correct framebuffers, even tried patching dp port to hdmi, in which I succeeded, I could see HDMI framebuffer from IOReg, but this still didn't seem to fix my issue, both ports work separately well, but not together, without sleep - wake anyways.

SMBIOS: iMac17,1
MOBO: Asus Z97m-Plus
GPU: Asus R9 390 DC-2
CPU: 4690k

All kexts are latest, OC 0.7.5, unfortunately haven't found a way to debug Lilu and Whatevergreen, I can see debug log on startup, but it doesn't dump a file.

 

[wwatu]

Now my GPU decided to output to all outputs on boot, so I changed back to DVI with DVI-HDMI adapter, and TV on HDMI port, had to still patch DVI framebuffer to HDMI to allow audio over DVI, but everything seems to work as expected right now. Attached patched SSDT if anyone cares.

 

[Westsurf]

Ive been given a MSI R9 390 which I’m considering trying to use.

Thanks for this post as it may help me.