drm/virtio: move the check for vqs_ready earlier

When vqs_ready is false, vq should be considered invalid and we
should not check vq->num_free.  After this change, a fenced command
queued before the vqs are ready will have fence id 0 and will be
considered done.
Signed-off-by: NChia-I Wu <olvaffe@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200205181955.202485-9-olvaffe@gmail.comSigned-off-by: NGerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/virtio/virtgpu_vq.c

@@ -333,6 +333,14 @@ static bool virtio_gpu_queue_ctrl_sgs(struct virtio_gpu_device *vgdev,
 again:
 	spin_lock(&vgdev->ctrlq.qlock);
 
+	if (!vgdev->vqs_ready) {
+		spin_unlock(&vgdev->ctrlq.qlock);
+
+		if (fence && vbuf->objs)
+			virtio_gpu_array_unlock_resv(vbuf->objs);
+		return notify;
+	}
+
 	if (vq->num_free < elemcnt) {
 		spin_unlock(&vgdev->ctrlq.qlock);
 		wait_event(vgdev->ctrlq.ack_queue, vq->num_free >= elemcnt);
@@ -351,11 +359,6 @@ static bool virtio_gpu_queue_ctrl_sgs(struct virtio_gpu_device *vgdev,
 		}
 	}
 
-	if (!vgdev->vqs_ready) {
-		spin_unlock(&vgdev->ctrlq.qlock);
-		return notify;
-	}
-
 	ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
 	WARN_ON(ret);