BLE_GATTC_EVT_WRITE_RSP event is received why is write_rsp.len is equal to 0

[perry_huang]

I try to send NRF_DFU_OP_PING reqeust ,then received BLE_GATTC_EVT_WRITE_RSP message. but write_rsp.len is equal to  0,.I can see gatt_status is  BLE_GATT_STATUS_SUCCESS. I don't understand.

[Susheel Nuguru]

what is the length value you receive in the BLE_GATTC_EVT_WRITE_RSP? (p_ble_evt->evt.gattc_evt.params.write_rsp.len)