[PATCH 5.6 039/166] drm/ttm: flush the fence on the bo after we individualize the reservation object

[Greg Kroah-Hartman]

From: xinhui pan <xinhui.pan@xxxxxxx>

[ Upstream commit 1bbcf69e42fe7fd49b6f4339c970729d0e343753 ]

As we move the ttm_bo_individualize_resv() upwards, we need flush the
copied fence too. Otherwise the driver keeps waiting for fence.

run&Kill kfdtest, then perf top.

  25.53%  [ttm]                     [k] ttm_bo_delayed_delete
  24.29%  [kernel]                  [k] dma_resv_test_signaled_rcu
  19.72%  [kernel]                  [k] ww_mutex_lock

Fix: 378e2d5b("drm/ttm: fix ttm_bo_cleanup_refs_or_queue once more")
Signed-off-by: xinhui pan <xinhui.pan@xxxxxxx>
Reviewed-by: Christian KÃnig <christian.koenig@xxxxxxx>
Link: https://patchwork.freedesktop.org/series/72339/
Signed-off-by: Christian KÃnig <christian.koenig@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 5df596fb0280c..fe420ca454e0a 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -498,8 +498,10 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
 
 		dma_resv_unlock(bo->base.resv);
 	}
-	if (bo->base.resv != &bo->base._resv)
+	if (bo->base.resv != &bo->base._resv) {
+		ttm_bo_flush_all_fences(bo);
 		dma_resv_unlock(&bo->base._resv);
+	}
 
 error:
 	kref_get(&bo->list_kref);
-- 
2.20.1