stty: problem if IXON enabled and DC3 char was received

[Tomas Krcka]

Hi,
  I had a problem with setting baudrate of serial line by stty command.
I tried to change the baudrate, but the stty went to frozen state.
I found out that problem is that kernel has IXON enabled as default and before change of speed the line received DC3 char. It's illegal character in this situation, it happens once per 100 starts of the system.

Example situation:
   IXON is enabled in kernel by default and a serial line received DC3 char and then you can not disable IXON. There is waiting for empty buffer in kernel but sending is stopped because of DC3 char.
 
If TCSADRAIN is changed to TCSANOW then it's correct.

Do you have any opinion about the situation ? Is it possible to change TCSADRAIN to TCSANOW or create a new parameter of stty to change the serial line settings immediately ?

Thanks,
Tomas