Request for advice in tracking down a kernel panic related to amdgpu.

Hello,

I recently noticed that if you launch a program that uses an AMD GPU
via OpenGL or Vulkan, and that specific GPU is not being used as a
display output (typical in GPGPU use-cases for example), a kernel
panic results. I've opened a bug report on github with drm-kmod, but I
would also like to dig into this on my own, though I'm new to FreeBSD.

The actual panic is caused by a "page fault in kernel mode". My naive
suspicion is that when a GPU is used for display output there is some
sort of initialization that takes place, which is required for Vulkan
and OpenGL to work correctly, and when this has not been done, an
uninitialized resource is accessed. If that sounds reasonable, does
anybody know where in the FreeBSD or drm-kmod code base I might start
looking to find this missing initialization? I apologize if this is
clearly documented somewhere, I did look, but failed to find it...

Thanks,
Harris Snyder