drm/virtio: batch display query

Move virtio_gpu_notify() to higher-level functions for
virtio_gpu_cmd_get_display_info() and virtio_gpu_cmd_get_edids().

virtio_gpu_config_changed_work_func() and virtio_gpu_init() will
batch commands and notify only once per update
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NChia-I Wu <olvaffe@gmail.com>
Reviewed-by: NGurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200214125535.26349-6-kraxel@redhat.com

drivers/gpu/drm/virtio/virtgpu_kms.c

@@ -44,6 +44,7 @@ static void virtio_gpu_config_changed_work_func(struct work_struct *work)
 		if (vgdev->has_edid)
 			virtio_gpu_cmd_get_edids(vgdev);
 		virtio_gpu_cmd_get_display_info(vgdev);
+		virtio_gpu_notify(vgdev);
 		drm_helper_hpd_irq_event(vgdev->ddev);
 		events_clear |= VIRTIO_GPU_EVENT_DISPLAY;
 	}
@@ -205,6 +206,7 @@ int virtio_gpu_init(struct drm_device *dev)
 	if (vgdev->has_edid)
 		virtio_gpu_cmd_get_edids(vgdev);
 	virtio_gpu_cmd_get_display_info(vgdev);
+	virtio_gpu_notify(vgdev);
 	wait_event_timeout(vgdev->resp_wq, !vgdev->display_info_pending,
 			   5 * HZ);
 	return 0;

drivers/gpu/drm/virtio/virtgpu_vq.c

@@ -775,7 +775,6 @@ int virtio_gpu_cmd_get_display_info(struct virtio_gpu_device *vgdev)
 	vgdev->display_info_pending = true;
 	cmd_p->type = cpu_to_le32(VIRTIO_GPU_CMD_GET_DISPLAY_INFO);
 	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
-	virtio_gpu_notify(vgdev);
 	return 0;
 }
 
@@ -903,7 +902,6 @@ int virtio_gpu_cmd_get_edids(struct virtio_gpu_device *vgdev)
 		cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_GET_EDID);
 		cmd_p->scanout = cpu_to_le32(scanout);
 		virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
-		virtio_gpu_notify(vgdev);
 	}
 
 	return 0;