[PATCH 08/10] drm/ttm: cope with reserved buffers on lru list in ttm_mem_evict_first

[Maarten Lankhorst <m.b.lankhorst@gmail.com>]

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index b9c26a5..a760178 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -779,26 +779,21 @@ static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
 	struct ttm_bo_global *glob = bdev->glob;
 	struct ttm_mem_type_manager *man = &bdev->man[mem_type];
 	struct ttm_buffer_object *bo;
-	int ret, put_count = 0;
+	int ret = -EBUSY, put_count = 0;
 
 	spin_lock(&glob->lru_lock);
-	if (list_empty(&man->lru)) {
-		spin_unlock(&glob->lru_lock);
-		return -EBUSY;
+	list_for_each_entry(bo, &man->lru, lru) {
+		ret = ttm_bo_reserve_locked(bo, false, true, false, 0);
+		if (!ret)
+			break;
 	}
 
-	bo = list_first_entry(&man->lru, struct ttm_buffer_object, lru);
-	kref_get(&bo->list_kref);
-
-	ret = ttm_bo_reserve_locked(bo, false, true, false, 0);
-
-	if (WARN_ON_ONCE(ret == -EBUSY)) {
+	if (ret) {
 		spin_unlock(&glob->lru_lock);
-
-		kref_put(&bo->list_kref, ttm_bo_release_list);
 		return ret;
 	}
 
+	kref_get(&bo->list_kref);
 	if (!list_empty(&bo->ddestroy)) {
 		ret = ttm_bo_cleanup_refs_and_unlock(bo, interruptible,
 						     no_wait_gpu);
-- 
1.8.0