Description of problem:
This problem is already in bug 73376, but since that one is public and seems to
be left alone, I'm filing this just as a reminder, close as you wish.

There seem to be a problem in select() and or serial line management, where
mgetty  is not notified something is using serial line; this way mgetty cannot
reset modem with init-chat after process terminates using serial line.

How reproducible:
always
1. have mgetty on the line
2. cu -l ttyS0, type some char
3. note how in log mgetty is still waiting for chars on ttyS0
4. terminate cu
5. note in mgetty log init-chat is not rerun

  
As reported in 73376, vanilla kernels are OK.