Curious BeagleBone console hang...

[Tim Kientzle]

Here's an odd one:

$ stty 72

consistently hangs the serial console on a BeagleBone
running FreeBSD-CURRENT r264208.  (I found this out
by accidentally omitting 'rows' when I typed the command.)

Doesn't seem to affect an SSH session, only the serial console.

After doing this, nothing seems to be running; the console
is just completely non responsive: even echo is dead.

I can recover by logging in through SSH and killing the
console login.

Trying to puzzle it out:

$ truss stty 72
...
ioctl(0,TIOCGETA,0xbffffcb0)                     = 0 (0x0)
ioctl(0,TIOCGETD,0xbffffc9c)                     = 0 (0x0)
ioctl(0,TIOCGWINSZ,0xbffffcdc)                   = 0 (0x0)
ioctl(1,TIOCGETA,0xbffffb60)                     = 0 (0x0)
ioctl(2,TIOCGETA,0xbffffb60)                     = 0 (0x0)
fstat(1,{ mode=crw------- ,inode=32,size=0,blksize=4096 }) = 0 (0x0)
fstat(2,{ mode=crw------- ,inode=32,size=0,blksize=4096 }) = 0 (0x0


Does this make sense to anyone?

Tim