[Intel-gfx] [PATCH] Add some sanity checks to unbound tracking

[Chris Wilson]

A pair of universally true checks that just need to be put in the right
place depending on where in the patch sequence you go. Note that
i915_gem_object_put_pages_gtt() already gains the
BUG_ON(obj->gtt_space), but on reflection that needed to migrate to
put_pages().

---
 drivers/gpu/drm/i915/i915_gem.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 0608d95..f90390a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1806,6 +1806,8 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
 {
 	const struct drm_i915_gem_object_ops *ops = obj->base.driver_private;
 
+	BUG_ON(obj->gtt_space);
+
 	if (obj->pages == NULL)
 		return 0;
 
@@ -2530,6 +2532,8 @@ i915_gem_object_unbind(struct drm_i915_gem_object *obj)
 	if (obj->pin_count)
 		return -EBUSY;
 
+	BUG_ON(obj->pages == NULL);
+
 	ret = i915_gem_object_finish_gpu(obj);
 	if (ret)
 		return ret;
-- 
1.7.10.4