debian bullseye testing kernel boots : custom hangs on boot

[hanasaki]

I have a custom built linux .deb kernel 5.10 that boots on bullseye and buster just fine; expect for only one of my computers, on which it hangs at "Loading initial ramdisk ...." The debian built kernels boot fine. Thoughts on what what might be the issue, how to fix or how to determine the root cause?
TIA

[Head_on_a_Stick]

Compare and contrast your configuration with Debian's (/boot/config-5.10.0-3-amd64).

[hanasaki]

Already tried that.... There are alot of diffs. suspect I missed something with framebuffers or he RAMdisk... Care to take a peek and suggest input?
config attached

[Head_on_a_Stick]

Care to take a peek and suggest input?

No.

[hanasaki]

amdgpu is in fact loaded; just not in use. Xorg seems to be picking up the ati driver instead of amdgpu

[Head_on_a_Stick]

https://wiki.archlinux.org/index.php/AMDGPU#Enable_Southern_Islands_(SI)_and_Sea_Islands_(CIK)_support

[hanasaki]

RESOLVED
The following must be NO in kernel .config file
CONFIG_AMD_MEM_ENCRYPT=n

info in dmesg / syslog
[    6.612898] amdgpu: Topology: Add APU node [0x0:0x0]
[    6.614183] amdgpu 0000:03:00.0: amdgpu: SME is not compatible with RAVEN
[    6.615259] amdgpu: probe of 0000:03:00.0 failed with error -524