USB: ch341: clean up line-status handling

Clean up line-status handling.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index f647dbdcb27dc94726f272fc583e705fb2454238..9dd94a7e08b91efaf03efd22835faa4c156d578f 100644 (file)
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -444,24 +444,30 @@ static void ch341_update_line_status(struct usb_serial_port *port,
                                        unsigned char *data, size_t len)
 {
        struct ch341_private *priv = usb_get_serial_port_data(port);
+       struct tty_struct *tty;
        unsigned long flags;
-       u8 prev_line_status = priv->line_status;
+       u8 status;
+       u8 delta;
 
        if (len < 4)
                return;
 
+       status = ~data[2] & CH341_BITS_MODEM_STAT;
+
        spin_lock_irqsave(&priv->lock, flags);
-       priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
-       if ((data[1] & CH341_MULT_STAT))
+       delta = status ^ priv->line_status;
+       priv->line_status = status;
+       if (data[1] & CH341_MULT_STAT)
                priv->multi_status_change = 1;
        spin_unlock_irqrestore(&priv->lock, flags);
 
-       if ((priv->line_status ^ prev_line_status) & CH341_BIT_DCD) {
-               struct tty_struct *tty = tty_port_tty_get(&port->port);
-               if (tty)
+       if (delta & CH341_BIT_DCD) {
+               tty = tty_port_tty_get(&port->port);
+               if (tty) {
                        usb_serial_handle_dcd_change(port, tty,
-                                       priv->line_status & CH341_BIT_DCD);
-               tty_kref_put(tty);
+                                               status & CH341_BIT_DCD);
+                       tty_kref_put(tty);
+               }
        }
 
        wake_up_interruptible(&port->port.delta_msr_wait);