From 95168d624f3a8dee466525767200391a0fb006b9 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 16 Nov 2020 17:18:21 +0100 Subject: [PATCH] USB: serial: cp210x: return early on unchanged termios Return early from set_termios() in case no relevant terminal settings have changed. This avoids testing each parameter in turn and specifically allows the line-control handling to be cleaned up further. Signed-off-by: Johan Hovold --- drivers/usb/serial/cp210x.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index d0c05aa8a0d6e..f1fd109d97d55 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -1352,6 +1352,15 @@ static void cp210x_disable_event_mode(struct usb_serial_port *port) port_priv->event_mode = false; } +static bool cp210x_termios_change(const struct ktermios *a, const struct ktermios *b) +{ + bool iflag_change; + + iflag_change = ((a->c_iflag ^ b->c_iflag) & INPCK); + + return tty_termios_hw_change(a, b) || iflag_change; +} + static void cp210x_set_termios(struct tty_struct *tty, struct usb_serial_port *port, struct ktermios *old_termios) { @@ -1359,6 +1368,9 @@ static void cp210x_set_termios(struct tty_struct *tty, unsigned int cflag, old_cflag; u16 bits; + if (!cp210x_termios_change(&tty->termios, old_termios)) + return; + cflag = tty->termios.c_cflag; old_cflag = old_termios->c_cflag; -- 2.30.2