AM625: run multiple serialcheck hang over half hours

Tool/software: SDK10.00.07.04

Customer reports running 3*2Mbps or 3*1.5Mbps serialcheck will hang after half hour.

UART DMA enabled.

Hardware setup: short TX/RX om the same UART port

serialcheck -b 2000000 -d /dev/ttyS6 -f ./binary_1w_ttyS6 -l 2786918 -m d &
serialcheck -b 2000000 -d /dev/ttyS7 -f ./binary_1w_ttyS7 -l 2786918 -m d &
serialcheck -b 2000000 -d /dev/ttyS8 -f ./binary_1w_ttyS8 -l 2786918 -m d &

Toggle ethernet up and down to trigger issue.

./eth_up_down.sh &

#!/bin/sh

for (( ; ; ))
  do
    ifconfig eth0 down
    sleep 1

    ifconfig eth0 up
    sleep 1
  done