[PATCH v2 15/22] usb: serial: ti_usb_3410_5052: Check old_termios parameter in set_termios

Mathieu OTHACEHE
2016-07-26T18:04:14Z

The old_termios parameter is never used in set_termios callback.

Add a check to old_termios to see if we can return right away because
there is nothing to change.

Also pass NULL for old_termios in open callback because it is the
initial call to set_termios.

Signed-off-by: Mathieu OTHACEHE <m.othacehe@gmail.com>
---
Changelog:
v2:
* Deal with DTR and RTS raising in the next patch.

drivers/usb/serial/ti_usb_3410_5052.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index b5ea850..d488237 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -740,7 +740,7 @@ static int ti_open(struct tty_struct *tty, struct usb_serial_port *port)
}

if (tty)
- ti_set_termios(tty, port, &tty->termios);
+ ti_set_termios(tty, port, NULL);

status = ti_send_ctrl_urb(serial, TI_OPEN_PORT, open_settings,
TI_UART1_PORT + port_number);
@@ -780,7 +780,7 @@ static int ti_open(struct tty_struct *tty, struct usb_serial_port *port)
usb_clear_halt(dev, port->read_urb->pipe);

if (tty)
- ti_set_termios(tty, port, &tty->termios);
+ ti_set_termios(tty, port, NULL);

status = ti_send_ctrl_urb(serial, TI_OPEN_PORT, open_settings,
TI_UART1_PORT + port_number);
@@ -993,6 +993,13 @@ static void ti_set_termios(struct tty_struct *tty,
cflag = tty->termios.c_cflag;
iflag = tty->termios.c_iflag;

+ if (old_termios &&
+ !tty_termios_hw_change(&tty->termios, old_termios) &&
+ tty->termios.c_iflag == old_termios->c_iflag) {
+ dev_dbg(&port->dev, "%s - nothing to change\n", __func__);
+ return;
+ }
+
dev_dbg(&port->dev,
"%s - cflag 0x%08x, iflag 0x%08x\n", __func__, cflag, iflag);

--
2.9.0