bingung dengan CI metode upload gan..

dashboard.php

class Dashboard extends CI_Controller {

    function Dashboard()
    {
        parent::__construct();

        if(!$this->session->userdata('logged'))
            redirect('login');
    }

    public function index()
    {
        $this->load->model('upload_model');
        $data['page_title']  = "Dashboard";

        // Load View
        $this->template->show('dashboard', $data);

        if($this->input->post('upload')){
            $this->upload_model->do_upload();
        }
        $this->load->view('upload_form');
    }

    public function doUpload(){
        $config = array(
            'upload_path' => 'member/',
            'allowed_types'=> 'png|jpg|jpeg',
            'max_size'=> '1000',
            'max_width'=> '1920',
            'max_height'=> '1200'
        );

        $this->load->library('upload', $config);
        if(!$this->upload->do_upload()){
            $error = array('error' => $this->upload->display_errors());

        }else{
            $finfo = $this->upload->data();
            echo '<pre>';
            //dapatkan info file
            print_r($finfo);
            echo '<pre>';
            $this->_createThumbnail($finfo['file_name']);

            $data['uploadInfo'] = $finfo;
            $data['thumbnail_name'] = $finfo['raw_name'] . '_profile' . $finfo['file_ext'];

            $this->load->view('upload_success',$data);
        }

    }

    function _createThumbnail($filename){
        $config = array(
            'image_library' => 'gd2',
            'source_image' => 'member/' . $filename,
            'new_image' => 'member/profile',
            'create_thumb' => 'true',
            'maintain_ratio' => 'true',
            'width' => 150,
            'height' => 175
        );
        $this->load->library('image_lib',$config);
        if(!$this->image_lib->resize())
            echo $this->image_lib->display_errors();

    }


}


upload_model.php
<?php

class Upload_model extends CI_Model{
    //var $image_path;

    function Upload_model(){
        parent::__construct();

        //$image_path = realpath(APPPATH . './member');
    }
    public function do_upload()
    {

    $config = array(
        'allowed_type' => 'gif|jpg|png|jpeg|JPG',
        'upload_path' => './member/',
        'max_size' => '1024',
        'max_height' => '768'
    );


    $this->load->library('upload', $config);
    $this->upload->do_upload();

        $image_data = $this->upload->data();

        $config = array(
            'source_image' => $image_data['full_path'],
            'new_image' => './member/thumbs',
            'maintain_ration' => true,
            'width' => 150,
            'height' => 100
        );
    $this->load->library('image_lib',$config);
    $this->image_lib->resize();
    }
}