CCS/CC2640R2F: How to add a central device to a whitelist in CC2640R2 ?

Tool/software: Code Composer Studio

    I want to imply the following feature: CC2640R2 launchpad  advertises normally and acts as a peripheral device. My iphone acts as a

central device. As long as my iphone connects with CC2640R2, it saves the address of my iphone to the whitelist and changes the

advertising mode to  White List Only. As a result ,only my iphone can connect with this CC2640R2. 

    However, I failed to add my iphone to the whitelist. HCI_LE_ReadWhiteListSizeCmd()  keeps return 0 . My code is as followed. 
1、My code is written according to this post:
https://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/p/417407/1845109?tisearch=e2e-sitesearch&keymatch=cc2640%20%20whitelist#1845109

2、simple_peripheral.c

    case GAPROLE_CONNECTED:
      {

        //参数定义
        uint8 adv_filter = GAP_FILTER_POLICY_WHITE;
        uint8 remoteBdAddr[B_ADDR_LEN] = {0};
        //获取已连接的设备的地址
        GAPRole_GetParameter(GAPROLE_CONN_BD_ADDR, remoteBdAddr);
        //设置广播模式为白名单模式
        GAPRole_SetParameter( GAPROLE_ADV_FILTER_POLICY, sizeof( uint8 ), &adv_filter );
        //清空白名单
        HCI_LE_ClearWhiteListCmd();
        //将已连接的设备的地址添加到白名单中
        HCI_LE_AddWhiteListCmd( HCI_PUBLIC_DEVICE_ADDRESS, remoteBdAddr );

        ........

      }

3、peripheral.c

      if (events & START_ADVERTISING_EVT)
      {

        //读取白名单的大小
        uint8 WL = HCI_LE_ReadWhiteListSizeCmd();
        //whiteListNum为白名单的大小 ，whiteListNum为全局变量。
        if(WL>0 )
        {
          gapRole_AdvFilterPolicy = GAP_FILTER_POLICY_WHITE;
          whiteListNum = WL;
        }
        //whiteListNum为白名单的大小
        else
        {
          gapRole_AdvFilterPolicy = GAP_FILTER_POLICY_ALL;
          whiteListNum = 0;
        }

      .........

    }

4、My complete workspace can be got from here:

CCSworkspace121.rar

5、My code is based on the simple_peripheral project in CC2640R2 SDK -v:1.40.00.45 .  CC2640R2 SDK -v:1.40.00.45 is downloaded from here: