USB: ch341: set tty baud speed according to tty struct

commit aa91def41a7bb1fd65492934ce6bea19202b6080 upstream.

The ch341_set_baudrate() function initialize the device baud speed
according to the value on priv->baud_rate. By default the ch341_open() set
it to a hardcoded value (DEFAULT_BAUD_RATE 9600). Unfortunately, the
tty_struct is not initialized with the same default value. (usually 56700)

This means that the tty_struct and the device baud rate generator are not
synchronized after opening the port.

Fixup is done by calling ch341_set_termios() if tty exist.
Remove unnecessary variable priv->baud_rate setup as it's already done by
ch341_port_probe().
Remove unnecessary call to ch341_set_{handshake,baudrate}() in
ch341_open() as there already called in ch341_configure() and
ch341_set_termios()

Signed-off-by: Nicolas PLANEL <nicolas.planel@enovance.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 5b27f5e..fef839b 100644 (file)
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -88,6 +88,10 @@ struct ch341_private {
        u8 multi_status_change; /* status changed multiple since last call */
 };
 
        u8 multi_status_change; /* status changed multiple since last call */
 };
 

+static void ch341_set_termios(struct tty_struct *tty,
+                             struct usb_serial_port *port,
+                             struct ktermios *old_termios);
+

 static int ch341_control_out(struct usb_device *dev, u8 request,
                             u16 value, u16 index)
 {
 static int ch341_control_out(struct usb_device *dev, u8 request,
                             u16 value, u16 index)
 {


@@ -318,19 +322,12 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
 
        dbg("ch341_open()");
 
 
        dbg("ch341_open()");
 

-       priv->baud_rate = DEFAULT_BAUD_RATE;
-

        r = ch341_configure(serial->dev, priv);
        if (r)
                goto out;
 
        r = ch341_configure(serial->dev, priv);
        if (r)
                goto out;
 

-       r = ch341_set_handshake(serial->dev, priv->line_control);
-       if (r)
-               goto out;
-
-       r = ch341_set_baudrate(serial->dev, priv);
-       if (r)
-               goto out;
+       if (tty)
+               ch341_set_termios(tty, port, NULL);

 
        dbg("%s - submitting interrupt urb", __func__);
        port->interrupt_in_urb->dev = serial->dev;
 
        dbg("%s - submitting interrupt urb", __func__);
        port->interrupt_in_urb->dev = serial->dev;