USB: serial: cp210x: update control-characters on every change

Update the XON/XOFF control characters also when no other flow-control
flag has changed and software flow control is enabled.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index ee0139e..4f90573 100644 (file)
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -1113,11 +1113,13 @@ static int cp210x_set_chars(struct usb_serial_port *port,
 
 static bool cp210x_termios_change(const struct ktermios *a, const struct ktermios *b)
 {
-       bool iflag_change;
+       bool iflag_change, cc_change;
 
        iflag_change = ((a->c_iflag ^ b->c_iflag) & (INPCK | IXON | IXOFF));
+       cc_change = a->c_cc[VSTART] != b->c_cc[VSTART] ||
+                       a->c_cc[VSTOP] != b->c_cc[VSTOP];
 
-       return tty_termios_hw_change(a, b) || iflag_change;
+       return tty_termios_hw_change(a, b) || iflag_change || cc_change;
 }
 
 static void cp210x_set_flow_control(struct tty_struct *tty,
@@ -1132,7 +1134,9 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
        if (old_termios &&
                        C_CRTSCTS(tty) == (old_termios->c_cflag & CRTSCTS) &&
                        I_IXON(tty) == (old_termios->c_iflag & IXON) &&
-                       I_IXOFF(tty) == (old_termios->c_iflag & IXOFF)) {
+                       I_IXOFF(tty) == (old_termios->c_iflag & IXOFF) &&
+                       START_CHAR(tty) == old_termios->c_cc[VSTART] &&
+                       STOP_CHAR(tty) == old_termios->c_cc[VSTOP]) {
                return;
        }