drm/i915: Move flushing list cleanup from flush request retire to request emit.

obj_priv->write_domain is "write domain if the GPU went idle now", not
"write domain at this moment."  By postponing the clear, we confused the
concept, required more storage, and potentially emitted more flushes than
are required.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d58ddef..9fd28eb 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -532,7 +532,7 @@
 }
 
 static void
-i915_gem_object_move_to_active(struct drm_gem_object *obj)
+i915_gem_object_move_to_active(struct drm_gem_object *obj, uint32_t seqno)
 {
 	struct drm_device *dev = obj->dev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
@@ -546,8 +546,20 @@
 	/* Move from whatever list we were on to the tail of execution. */
 	list_move_tail(&obj_priv->list,
 		       &dev_priv->mm.active_list);
+	obj_priv->last_rendering_seqno = seqno;
 }
 
+static void
+i915_gem_object_move_to_flushing(struct drm_gem_object *obj)
+{
+	struct drm_device *dev = obj->dev;
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	struct drm_i915_gem_object *obj_priv = obj->driver_private;
+
+	BUG_ON(!obj_priv->active);
+	list_move_tail(&obj_priv->list, &dev_priv->mm.flushing_list);
+	obj_priv->last_rendering_seqno = 0;
+}
 
 static void
 i915_gem_object_move_to_inactive(struct drm_gem_object *obj)
@@ -562,6 +574,7 @@
 	else
 		list_move_tail(&obj_priv->list, &dev_priv->mm.inactive_list);
 
+	obj_priv->last_rendering_seqno = 0;
 	if (obj_priv->active) {
 		obj_priv->active = 0;
 		drm_gem_object_unreference(obj);
@@ -610,10 +623,28 @@
 
 	request->seqno = seqno;
 	request->emitted_jiffies = jiffies;
-	request->flush_domains = flush_domains;
 	was_empty = list_empty(&dev_priv->mm.request_list);
 	list_add_tail(&request->list, &dev_priv->mm.request_list);
 
+	/* Associate any objects on the flushing list matching the write
+	 * domain we're flushing with our flush.
+	 */
+	if (flush_domains != 0) {
+		struct drm_i915_gem_object *obj_priv, *next;
+
+		list_for_each_entry_safe(obj_priv, next,
+					 &dev_priv->mm.flushing_list, list) {
+			struct drm_gem_object *obj = obj_priv->obj;
+
+			if ((obj->write_domain & flush_domains) ==
+			    obj->write_domain) {
+				obj->write_domain = 0;
+				i915_gem_object_move_to_active(obj, seqno);
+			}
+		}
+
+	}
+
 	if (was_empty && !dev_priv->mm.suspended)
 		schedule_delayed_work(&dev_priv->mm.retire_work, HZ);
 	return seqno;
@@ -676,30 +707,10 @@
 			 __func__, request->seqno, obj);
 #endif
 
-		if (obj->write_domain != 0) {
-			list_move_tail(&obj_priv->list,
-				       &dev_priv->mm.flushing_list);
-		} else {
+		if (obj->write_domain != 0)
+			i915_gem_object_move_to_flushing(obj);
+		else
 			i915_gem_object_move_to_inactive(obj);
-		}
-	}
-
-	if (request->flush_domains != 0) {
-		struct drm_i915_gem_object *obj_priv, *next;
-
-		/* Clear the write domain and activity from any buffers
-		 * that are just waiting for a flush matching the one retired.
-		 */
-		list_for_each_entry_safe(obj_priv, next,
-					 &dev_priv->mm.flushing_list, list) {
-			struct drm_gem_object *obj = obj_priv->obj;
-
-			if (obj->write_domain & request->flush_domains) {
-				obj->write_domain = 0;
-				i915_gem_object_move_to_inactive(obj);
-			}
-		}
-
 	}
 }
 
@@ -896,17 +907,15 @@
 	 * create a new seqno to wait for.
 	 */
 	if (obj->write_domain & ~(I915_GEM_DOMAIN_CPU|I915_GEM_DOMAIN_GTT)) {
-		uint32_t write_domain = obj->write_domain;
+		uint32_t seqno, write_domain = obj->write_domain;
 #if WATCH_BUF
 		DRM_INFO("%s: flushing object %p from write domain %08x\n",
 			  __func__, obj, write_domain);
 #endif
 		i915_gem_flush(dev, 0, write_domain);
 
-		i915_gem_object_move_to_active(obj);
-		obj_priv->last_rendering_seqno = i915_add_request(dev,
-								  write_domain);
-		BUG_ON(obj_priv->last_rendering_seqno == 0);
+		seqno = i915_add_request(dev, write_domain);
+		i915_gem_object_move_to_active(obj, seqno);
 #if WATCH_LRU
 		DRM_INFO("%s: flush moves to exec list %p\n", __func__, obj);
 #endif
@@ -1927,10 +1936,8 @@
 	i915_file_priv->mm.last_gem_seqno = seqno;
 	for (i = 0; i < args->buffer_count; i++) {
 		struct drm_gem_object *obj = object_list[i];
-		struct drm_i915_gem_object *obj_priv = obj->driver_private;
 
-		i915_gem_object_move_to_active(obj);
-		obj_priv->last_rendering_seqno = seqno;
+		i915_gem_object_move_to_active(obj, seqno);
 #if WATCH_LRU
 		DRM_INFO("%s: move to exec list %p\n", __func__, obj);
 #endif