drm/i915: Remove obsolete i915_gem_object_flush_active()

Since we track requests, and requests are always added to the GPU fully
formed, we never have to flush the incomplete request and know that the
given request will eventually complete without any further action on our
part.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-15-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem.c

@@ -2745,35 +2745,6 @@ out_rearm:
 	}
 }
 
-/**
- * Ensures that an object will eventually get non-busy by flushing any required
- * write domains, emitting any outstanding lazy request and retiring and
- * completed requests.
- * @obj: object to flush
- */
-static int
-i915_gem_object_flush_active(struct drm_i915_gem_object *obj)
-{
-	int i;
-
-	if (!obj->active)
-		return 0;
-
-	for (i = 0; i < I915_NUM_ENGINES; i++) {
-		struct drm_i915_gem_request *req;
-
-		req = i915_gem_active_peek(&obj->last_read[i],
-					   &obj->base.dev->struct_mutex);
-		if (req == NULL)
-			continue;
-
-		if (i915_gem_request_completed(req))
-			i915_gem_object_retire__read(obj, i);
-	}
-
-	return 0;
-}
-
 /**
  * i915_gem_wait_ioctl - implements DRM_IOCTL_I915_GEM_WAIT
  * @dev: drm device pointer
@@ -2820,24 +2791,9 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		return -ENOENT;
 	}
 
-	/* Need to make sure the object gets inactive eventually. */
-	ret = i915_gem_object_flush_active(obj);
-	if (ret)
-		goto out;
-
 	if (!obj->active)
 		goto out;
 
-	/* Do this after OLR check to make sure we make forward progress polling
-	 * on this IOCTL with a timeout == 0 (like busy ioctl)
-	 */
-	if (args->timeout_ns == 0) {
-		ret = -ETIME;
-		goto out;
-	}
-
-	i915_gem_object_put(obj);
-
 	for (i = 0; i < I915_NUM_ENGINES; i++) {
 		struct drm_i915_gem_request *req;
 
@@ -2847,6 +2803,8 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 			requests[n++] = req;
 	}
 
+out:
+	i915_gem_object_put(obj);
 	mutex_unlock(&dev->struct_mutex);
 
 	for (i = 0; i < n; i++) {
@@ -2857,11 +2815,6 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		i915_gem_request_put(requests[i]);
 	}
 	return ret;
-
-out:
-	i915_gem_object_put(obj);
-	mutex_unlock(&dev->struct_mutex);
-	return ret;
 }
 
 static int
@@ -4032,13 +3985,8 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 
 	/* Count all active objects as busy, even if they are currently not used
 	 * by the gpu. Users of this interface expect objects to eventually
-	 * become non-busy without any further actions, therefore emit any
-	 * necessary flushes here.
+	 * become non-busy without any further actions.
 	 */
-	ret = i915_gem_object_flush_active(obj);
-	if (ret)
-		goto unref;
-
 	args->busy = 0;
 	if (obj->active) {
 		struct drm_i915_gem_request *req;
@@ -4056,7 +4004,6 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
 			args->busy |= req->engine->exec_id;
 	}
 
-unref:
 	i915_gem_object_put(obj);
 unlock:
 	mutex_unlock(&dev->struct_mutex);