[PATCH 01/11] tty_port: Move hupcl handling

Alan Cox
2009-11-03T14:30:48Z

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>
---

drivers/char/tty_port.c | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index da12fae..cf4b16a 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -357,6 +357,14 @@ 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 */
@@ -368,11 +376,6 @@ 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;