USB: serial: ch341: fix open and resume after B0

commit a20047f36e2f6a1eea4f1fd261aaa55882369868 upstream.

The private baud_rate variable is used to configure the port at open and
reset-resume and must never be set to (and left at) zero or reset-resume
and all further open attempts will fail.

Fixes: aa91def41a7b ("USB: ch341: set tty baud speed according to tty struct")
Fixes: 664d5df92e88 ("USB: usb-serial ch341: support for DTR/RTS/CTS")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 974c90e0ddd83ae64f1090058c754dea1e7798e3..fa4d6aca54ec4d48880af0f01805a56d5d86f5f6 100644 (file)
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -361,12 +361,11 @@ static void ch341_set_termios(struct tty_struct *tty,
 
        baud_rate = tty_get_baud_rate(tty);
 
-       priv->baud_rate = baud_rate;
-
        if (baud_rate) {
                spin_lock_irqsave(&priv->lock, flags);
                priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
                spin_unlock_irqrestore(&priv->lock, flags);
+               priv->baud_rate = baud_rate;
                ch341_set_baudrate(port->serial->dev, priv);
        } else {
                spin_lock_irqsave(&priv->lock, flags);