[BISECTED] Horizon Zero Dawn won't start on 6800M Navy Flounder

Split from #1927 (closed)

The first kernel commit that stops the game from playing is:

dfa714b88eb0a9d763eba9e5720b089a58dc9496 is the first bad commit
commit dfa714b88eb0a9d763eba9e5720b089a58dc9496
Author: Christian König <christian.koenig@amd.com>
Date:   Mon Jul 12 15:18:05 2021 +0200

    drm/amdgpu: remove GTT accounting v2
    
    This is provided by TTM now.
    
    Also switch man->size to bytes instead of pages and fix the double
    printing of size and usage in debugfs.
    
    v2: fix size checking as well
    
    Signed-off-by: Christian König <christian.koenig@amd.com>
    Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
    Reviewed-by: Matthew Auld <matthew.auld@intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20220214093439.2989-6-christian.koenig@amd.com

 drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c | 49 +++++++----------------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c     |  8 ++---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c  |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h     |  2 --
 4 files changed, 16 insertions(+), 45 deletions(-)

I've tried reverting 7db47b838896ec2bb57e3d0b329804b84f32626c 3fc2b087df2ce87dc11abe4a5e7a02b75b5bb82e and dfa714b88eb0a9d763eba9e5720b089a58dc9496 however there are still merge conflicts in drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h I'm guessing from the merge commit 54f43c17d681f6d9523fcfaeefc9df77993802e1