link trainning of rs780e is x2

Hello:
      everyone, the gfx configured as 2 x8 slot, 
after link trained successfully, I printed the width
, the value of which is 4. Does it means the link width
is x8? 
from the function dual_port_configuration 
......
                switch (width) {
                case 1:
                case 2:
                        nbpcie_ind_write_index(nb_dev, 0x65,
                                               cfg->gfx_lane_reversal ? 0x0000 : 0x0000);
                        tgt_printf("file %s, func %s, line %d, dev_ind %d width %d\n", __FILE__, __func__, __LINE__, dev_ind, width);
                        break;
                case 4:
                        tgt_printf("file %s, func %s, line %d, dev_ind %d width %d\n", __FILE__, __func__, __LINE__, dev_ind, width);
                        nbpcie_ind_write_index(nb_dev, 0x65,
                                               cfg->gfx_lane_reversal ? 0x0000 : 0x0000);
                        break;
......

Both dev2 and dev3's link width are 4 (x8?). Then I boot linux
use lspci -vvv as root, the result is

00:02.0
......
                 LnkCap: Port #0, Speed 5GT/s, Width x8,......
......
                 LnkSta: Speed 2.5GT/s, Width x2,......

It is the same to the dev3. The cb file is from 
src/mainboard/amd/mahogany_fam10/devicetree.cb

Anyone know about the link training of gfx of rs780e? Thanks.