[PATCH 2/2] drm/ttm: Move pinned objects off LRU lists when pinning

[Thomas Hellström]

The ttm_bo_pin() and ttm_bo_unpin() functions weren't moving their
resources off the LRU list to the unevictable list.

Make sure that happens so that pinned objects don't accidently linger
on the LRU lists, and also make sure to move them back once they
are unpinned.

Cc: Christian König <christian.koenig at amd.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Cc: <dri-devel at lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index d244566a7e48..057a65f51969 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -592,9 +592,10 @@ void ttm_bo_pin(struct ttm_buffer_object *bo)
 	dma_resv_assert_held(bo->base.resv);
 	WARN_ON_ONCE(!kref_read(&bo->kref));
 	spin_lock(&bo->bdev->lru_lock);
-	if (bo->resource)
+	if (!bo->pin_count++ && bo->resource) {
 		ttm_resource_del_bulk_move(bo->resource, bo);
-	++bo->pin_count;
+		ttm_resource_move_to_lru_tail(bo->resource);
+	}
 	spin_unlock(&bo->bdev->lru_lock);
 }
 EXPORT_SYMBOL(ttm_bo_pin);
@@ -613,9 +614,10 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo)
 		return;
 
 	spin_lock(&bo->bdev->lru_lock);
-	--bo->pin_count;
-	if (bo->resource)
+	if (!--bo->pin_count && bo->resource) {
 		ttm_resource_add_bulk_move(bo->resource, bo);
+		ttm_resource_move_to_lru_tail(bo->resource);
+	}
 	spin_unlock(&bo->bdev->lru_lock);
 }
 EXPORT_SYMBOL(ttm_bo_unpin);
-- 
2.46.0