USB: ch341: fix termios handling

The ch341 currently doesn't support most of the hardware setting.  So to keep
the termios data right we propogate the old termios hardware values back then
encode the speed.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 6b252ceb39a828b69b29b78b2dfdfdf572a88bbd..42582d49b69c8951391e6a0a03c48f15d3756662 100644 (file)
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -272,9 +272,6 @@ static void ch341_set_termios(struct usb_serial_port *port,
 
        dbg("ch341_set_termios()");
 
-       if (!tty || !tty->termios)
-               return;
-
        baud_rate = tty_get_baud_rate(tty);
 
        switch (baud_rate) {
@@ -299,6 +296,11 @@ static void ch341_set_termios(struct usb_serial_port *port,
         * (cflag & PARENB) : parity {NONE, EVEN, ODD}
         * (cflag & CSTOPB) : stop bits [1, 2]
         */
+
+        /* Copy back the old hardware settings */
+        tty_termios_copy_hw(tty->termios, old_termios);
+        /* And re-encode with the new baud */
+        tty_encode_baud_rate(tty, baud_rate, baud_rate);
 }
 
 static struct usb_driver ch341_driver = {