1 files changed, 26 insertions, 20 deletions

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index ab4cc277aa65..2830766f5b39 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -262,32 +262,40 @@ error:	kfree(priv);
         return r;
 }
 
-static void ch341_close(struct tty_struct *tty, struct usb_serial_port *port,
-                                struct file *filp)
+static int ch341_carrier_raised(struct usb_serial_port *port)
+{
+        struct ch341_private *priv = usb_get_serial_port_data(port);
+        if (priv->line_status & CH341_BIT_DCD)
+                return 1;
+        return 0;
+}
+
+static void ch341_dtr_rts(struct usb_serial_port *port, int on)
 {
         struct ch341_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
-        unsigned int c_cflag;
 
         dbg("%s - port %d", __func__, port->number);
+        /* drop DTR and RTS */
+        spin_lock_irqsave(&priv->lock, flags);
+        if (on)
+                priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
+        else
+                priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
+        spin_unlock_irqrestore(&priv->lock, flags);
+        ch341_set_handshake(port->serial->dev, priv->line_control);
+        wake_up_interruptible(&priv->delta_msr_wait);
+}
+
+static void ch341_close(struct usb_serial_port *port)
+{
+        dbg("%s - port %d", __func__, port->number);
 
         /* shutdown our urbs */
         dbg("%s - shutting down urbs", __func__);
         usb_kill_urb(port->write_urb);
         usb_kill_urb(port->read_urb);
         usb_kill_urb(port->interrupt_in_urb);
-
-        if (tty) {
-                c_cflag = tty->termios->c_cflag;
-                if (c_cflag & HUPCL) {
-                        /* drop DTR and RTS */
-                        spin_lock_irqsave(&priv->lock, flags);
-                        priv->line_control = 0;
-                        spin_unlock_irqrestore(&priv->lock, flags);
-                        ch341_set_handshake(port->serial->dev, 0);
-                }
-        }
-        wake_up_interruptible(&priv->delta_msr_wait);
 }
 
 
@@ -302,7 +310,6 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
         dbg("ch341_open()");
 
         priv->baud_rate = DEFAULT_BAUD_RATE;
-        priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
 
         r = ch341_configure(serial->dev, priv);
         if (r)
@@ -322,7 +329,7 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
         if (r) {
                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
                         " error %d\n", __func__, r);
-                ch341_close(tty, port, NULL);
+                ch341_close(port);
                 return -EPROTO;
         }
 
@@ -343,9 +350,6 @@ static void ch341_set_termios(struct tty_struct *tty,
 
         dbg("ch341_set_termios()");
 
-        if (!tty || !tty->termios)
-                return;
-
         baud_rate = tty_get_baud_rate(tty);
 
         priv->baud_rate = baud_rate;
@@ -568,6 +572,8 @@ static struct usb_serial_driver ch341_device = {
         .usb_driver        = &ch341_driver,
         .num_ports         = 1,
         .open              = ch341_open,
+        .dtr_rts           = ch341_dtr_rts,
+        .carrier_raised    = ch341_carrier_raised,
         .close             = ch341_close,
         .ioctl             = ch341_ioctl,
         .set_termios       = ch341_set_termios,