drm/amdgpu: fix prime teardown order

We unmapped imported DMA-bufs when the GEM handle was dropped, not when the
hardware was done with the buffere.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
CC: stable@vger.kernel.org
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c

@@ -36,8 +36,6 @@ void amdgpu_gem_object_free(struct drm_gem_object *gobj)
 	struct amdgpu_bo *robj = gem_to_amdgpu_bo(gobj);
 
 	if (robj) {
-		if (robj->gem_base.import_attach)
-			drm_prime_gem_destroy(&robj->gem_base, robj->tbo.sg);
 		amdgpu_mn_unregister(robj);
 		amdgpu_bo_unref(&robj);
 	}

drivers/gpu/drm/amd/amdgpu/amdgpu_object.c

@@ -56,6 +56,8 @@ static void amdgpu_ttm_bo_destroy(struct ttm_buffer_object *tbo)
 
 	amdgpu_bo_kunmap(bo);
 
+	if (bo->gem_base.import_attach)
+		drm_prime_gem_destroy(&bo->gem_base, bo->tbo.sg);
 	drm_gem_object_release(&bo->gem_base);
 	amdgpu_bo_unref(&bo->parent);
 	if (!list_empty(&bo->shadow_list)) {