remserial and usb converters

[Jason Mitchell <jmitchel%bigjar.com@localhost>]

Hello,

    I'm trying to set up a NetBSD appliance that will (among other 
things) allow access to devices connected by USB serial adapters. The 
USB serial adapter works -- using minicom I can access the far end 
device (a Cisco 819). However when I use remserial, there's a problem -- 
remserial doesn't open the TCP Port. Starting minicom on the same USB 
serial port (minicom -b 9600 -D /dev/ttyU0) fixes the problem (I do this 
while remserial is running). This is a custom appliance with everything 
in an embedded ramdisk but I have seen this problem on another evbarm 
box running a standard install.

   The remserial command is:

remserial -d -p 48310 -s "9600 sane" /dev/ttyu0 &

    The platform is evbarm/aarch64 (ODROID-C2). The serial adapter is 
identified as:

[     4.939771] uftdi0: FTDI (0x403) FT232R USB UART (0x6001), rev 
2.00/6.00, addr 3
[     4.939771] ucom0 at uftdi0 portno 1

And here's the output from some relevant commands.

    uname -a

NetBSD ARMNUK 9.1 NetBSD 9.1 (ARMNUK) #0: Fri May  7 19:41:32 UTC 2021  
root@BreakingBad:/root/obj/sys/arch/evbarm/compile/ARMNUK evbarm

    ls -al /dev/ttyU0

crw-------  1 66  wheel  74, 0 May 21 03:55 /dev/ttyU0

    stty -f /dev/ttyU0 -a
speed 9600 baud; 0 rows; 0 columns; queue = 1024; line = termios;
lflags: -icanon -isig -iexten -echo -echoe -echok -echoke -echonl
        -echoctl -echoprt -altwerase -noflsh -tostop -flusho -pendin
        -nokerninfo -extproc
iflags: -istrip -icrnl -inlcr -igncr -ixon -ixoff -ixany -imaxbel ignbrk
        -brkint -inpck -ignpar -parmrk
oflags: -opost -onlcr -ocrnl -oxtabs -onocr -onlret
cflags: cread cs8 -parenb -parodd -hupcl clocal -cstopb crtscts -mdmbuf
        -cdtrcts
cchars: discard = ^O; dsusp = ^Y; eof = ^D; eol = <undef>;
        eol2 = <undef>; erase = ^?; intr = ^C; kill = ^U; lnext = ^V;
        min = 1; quit = ^\; reprint = ^R; start = ^Q; status = ^T;
        stop = ^S; susp = ^Z; time = 5; werase = ^W;

    remserial is being run as root (currently the only user account on 
the box). I'll change that once things are working. Any help is greatly 
appreciated. Thanks!

Jason M.