[REQUEST] Whitelist RX 6400 for Lenovo m93p

[shim80]

Hello

I have my old Lenovo Thinkcentre m93p with i5 4570. I bough a AMD RX 6400 to have some light gaming in it.
However, when I installed it, the display didn't worked anymore... I could'nt even go to the bios...

I tried both PCie (x4 and x16), HDMI and DisplayPort, but it's didn't change anything.

Even the internal video port isn't working when the GPU is attached   . I don't get it... Is the motherboard block ANY display output when he detect dedicated GPU ??

Anyway, I finally managed to get the display to work with GPU inside. I had to remove it, go to BIOS, and set video mode to IGP only. By doing that, I was able to boot Windows and see my RX 6400 recognized... 
Even after AMD drivers installed, the GPU refuse to work. And going back to Bios to set the video mode to "auto" systematically disable any display

I've updated my bios to the last version using the official driver from Lenovo (here https://download.lenovo.com/pccbbs/think...ye0usa.exe (here: https://download.lenovo.com/pccbbs/think...ye0usa.exe )
The problem is still here...

I've heard about PCi priority settings in bios, but I couldn't find it in my bios.
I've even searched for it in AMIBCP, but there's just blank folders...


I'm not even sure that's a Bios problem, but I'm out of options...
Any help would be nice