Subject: Re: Hang up of serial ports on speed 0
To: Ian Dall <Ian.Dall@dsto.defence.gov.au>
From: John Nemeth <jnemeth@cue.bc.ca>
List: tech-kern
Date: 07/14/1998 20:43:56
On Jul 10,  9:51pm, Ian Dall wrote:
}
} Setting the serial port speed to zero is supposed to hangup the line,
} yet when I look at sys/dev/ic/com.c I see:
} 
} #if 0
} 	if (ospeed == 0)
} 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
} 	else
} 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
} #endif
} 
} Why has this been commented out? 
} This logic could in principle be in device independent code, but
} I can't see anywhere where this is done. Pointers appreciated.

     This explains the problem I was having with mgetty.  I'm curious
why this was done too.  This directly contradicts the documention, not
to mention the way UNIX has worked for eons.

}-- End of excerpt from Ian Dall