1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 63f7cc45bcac..7b8815ddf368 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -486,12 +486,22 @@ static void ch341_read_int_callback(struct urb *urb)
         if (actual_length >= 4) {
                 struct ch341_private *priv = usb_get_serial_port_data(port);
                 unsigned long flags;
+                u8 prev_line_status = priv->line_status;
 
                 spin_lock_irqsave(&priv->lock, flags);
                 priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
                 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)
+                                usb_serial_handle_dcd_change(port, tty,
+                                            priv->line_status & CH341_BIT_DCD);
+                        tty_kref_put(tty);
+                }
+
                 wake_up_interruptible(&priv->delta_msr_wait);
         }