Currently I can send ctrl+c to the repeated line BOOTP broadcast 1 which restarts the dhcp process :

BOOTP broadcast 41
BOOTP broadcast 42
BOOTP broadcast 43
ipq807x_eth_halt: done

Abort
======== dhcp failed, retry !========
 confirm to launch xq_upgrade ! 
 cmd=dhcp

Net:   MAC0 addr:9c:9d:7e:1b:9e:f4
EDMA ver 1 hw init
Num rings - TxDesc:1 (0-0) TxCmpl:1 (7-7)
RxDesc:1 (15-15) RxFill:1 (7-7)
ipq807x_edma_alloc_rings: successfull
ipq807x_edma_setup_ring_resources: successfull
ipq807x_edma_configure_rings: successfull
ipq807x_edma_hw_init: successfull
board_eth_init: ipq807x_edma_init successed
, eth0
ipq807x_eth_halt: done
eth0 PHY0 Down Speed :10 Half duplex
eth0 PHY1 up Speed :10 Full duplex
eth0 PHY2 Down Speed :10 Half duplex
eth0 PHY3 Down Speed :10 Half duplex
eth0 PHY4 Down Speed :10 Half duplex
eth0 PHY5 Down Speed :10 Half duplex
ipq807x_eth_init: done
BOOTP broadcast 1
...