release/5.2.42/drm-ttm-flush-the-fence-on-the-bo-after-we-individua.patch

From 863ac6f38375f6dfbd52c37d551350892b3b477c Mon Sep 17 00:00:00 2001
From: xinhui pan <xinhui.pan@amd.com>
Date: Wed, 15 Jan 2020 14:07:45 +0800
Subject: [PATCH] drm/ttm: flush the fence on the bo after we individualize the
 reservation object
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commit 1bbcf69e42fe7fd49b6f4339c970729d0e343753 upstream.

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@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/series/72339/
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 2845fceb2fbd..720cc129369e 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -508,8 +508,10 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
 
 		reservation_object_unlock(bo->resv);
 	}
-	if (bo->resv != &bo->ttm_resv)
+	if (bo->resv != &bo->ttm_resv) {
+		ttm_bo_flush_all_fences(bo);
 		reservation_object_unlock(&bo->ttm_resv);
+	}
 
 error:
 	kref_get(&bo->list_kref);
-- 
2.7.4