tty_port: Move hupcl handling
Alan Cox [Thu, 5 Nov 2009 13:27:57 +0000 (13:27 +0000)]
Move the HUCPL handling from the end of close_port_start to the beginning
of close_port_end. What this actually does is change the ordering from

port shutdown
port->dtr_rts

to

port->dtr_rts
port shutdown

Some hardware drops the physical connection on shutdown so we must perform
the port operations before the shutdown.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/char/tty_port.c

index 41b314c..dd471d6 100644 (file)
@@ -339,6 +339,14 @@ int tty_port_close_start(struct tty_port *port,
                        timeout = 2 * HZ;
                schedule_timeout_interruptible(timeout);
        }
+       /* Flush the ldisc buffering */
+       tty_ldisc_flush(tty);
+
+       /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
+          hang up the line */
+       if (tty->termios->c_cflag & HUPCL)
+               tty_port_lower_dtr_rts(port);
+
        /* Don't call port->drop for the last reference. Callers will want
           to drop the last active reference in ->shutdown() or the tty
           shutdown path */
@@ -350,11 +358,6 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
 {
        unsigned long flags;
 
-       tty_ldisc_flush(tty);
-
-       if (tty->termios->c_cflag & HUPCL)
-               tty_port_lower_dtr_rts(port);
-
        spin_lock_irqsave(&port->lock, flags);
        tty->closing = 0;