diff options
| -rw-r--r-- | drivers/usb/serial/ch341.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index f647dbdcb27..9dd94a7e08b 100644 --- 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); |