UART1 and DM644X

I try to enable UART1 on DM6446 EVM

After some hacks, we have the following in booting messages

************************************************************************************

Serial: 8250/16550 driver $Revision: 1.90 $ 2 ports, IRQ sharing disabled
Registering platform device 'serial8250'. Parent at platform
ttyS0 at MMIO 0x1c20000 (irq = 40) is a 16550A
ttyS1 at MMIO 0x1c20400 (irq = 41) is a 16550A

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After login, I got the following when checking some status as suggested

# stty -a < /dev/ttyS1
speed 115200 baud; rows 24; columns 80;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W;
lnext = ^V; flush = ^O; min = 1; time = 0;
-parenb -parodd cs8 hupcl -cstopb cread clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff
-iuclc -ixany -imaxbel
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
echoctl echoke

# cat /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: uart:16550A port:00000000 irq:40 tx:7804 rx:346 RTS|CTS|DTR|DSR
1: uart:16550A port:00000000 irq:41 tx:0 rx:0 CTS|DSR

**************************************************************************************

when I do a "echo 1 > /dev/ttyS1", this command does not finish, I mean, I do not get a shell command prompt.

but if I do a "echo 1 > /dev/ttyS0", everything goes smoothly, I see "1" on remote PC console, and the command finishes up nicely with a shell command prompt.

Any ideas? Thanks. I have see discussion on DM355, but I could not get the UART1 to work on 6446 with suggested hacks.