[ Upstream commit 90ca78deb004abe75b5024968a199acb96bb70f9 ] This fixes an intermittent bug where a root PD clear operation still in progress could overwrite a PDE update done by the CPU, resulting in a VM fault. Fixes: 108b4d928c03 ("drm/amd/amdgpu: Update VM function pointer") Reported-by: Jay Cornwall <Jay.Cornwall@amd.com> Tested-by: Jay Cornwall <Jay.Cornwall@amd.com> Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>