diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
index 72bac3fb..c02360cf 100644
--- a/drivers/gpu/host1x/bus.c
+++ b/drivers/gpu/host1x/bus.c
@@ -938,6 +938,9 @@ struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo
 		mapping->cache = cache;
 
 		list_add_tail(&mapping->entry, &cache->mappings);
+
+		/* bump reference count to track the copy in the cache */
+		kref_get(&mapping->ref);
 	}
 
 unlock: