ttm_device_delayed_workqueue would reschedule itself if there is pending
BO to be destroyed. So just one flush + cancel_sync is not enough. We
still see lru_list not empty warnging.

Fix it by waiting all BO to be destroyed.

Signed-off-by: xinhui pan <xinhui.pan@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 6f47726f1765..e249923eb9a7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3957,11 +3957,17 @@ static void amdgpu_device_unmap_mmio(struct amdgpu_device *adev)
  */
 void amdgpu_device_fini_hw(struct amdgpu_device *adev)
 {
+       int pending = 1;
+
         dev_info(adev->dev, "amdgpu: finishing device.\n");
         flush_delayed_work(&adev->delayed_init_work);
-       if (adev->mman.initialized) {
+       while (adev->mman.initialized && pending) {
                 flush_delayed_work(&adev->mman.bdev.wq);
-               ttm_bo_lock_delayed_workqueue(&adev->mman.bdev);
+               pending = ttm_bo_lock_delayed_workqueue(&adev->mman.bdev);
+               if (pending) {
+                       ttm_bo_unlock_delayed_workqueue(&adev->mman.bdev, true);
+                       msleep((HZ / 100) < 1) ? 1 : HZ / 100);
+               }
         }
         adev->shutdown = true;
 
--
2.25.1