drm/i915: Assert all timeline requests are gone before fini

During i915_gem_timeline_fini(), assert that all the timeline's request
are completed and removed from the timeline.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170105153023.30575-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem_timeline.c

@@ -81,10 +81,18 @@ int i915_gem_timeline_init__global(struct drm_i915_private *i915)
 					&class, "&global_timeline->lock");
 }
 
-void i915_gem_timeline_fini(struct i915_gem_timeline *tl)
+void i915_gem_timeline_fini(struct i915_gem_timeline *timeline)
 {
-	lockdep_assert_held(&tl->i915->drm.struct_mutex);
+	int i;
 
-	list_del(&tl->link);
-	kfree(tl->name);
+	lockdep_assert_held(&timeline->i915->drm.struct_mutex);
+
+	for (i = 0; i < ARRAY_SIZE(timeline->engine); i++) {
+		struct intel_timeline *tl = &timeline->engine[i];
+
+		GEM_BUG_ON(!list_empty(&tl->requests));
+	}
+
+	list_del(&timeline->link);
+	kfree(timeline->name);
 }