USB: pl2303: clean up line-status handling
Clean up line-status handling somewhat.
Get tty-reference only when actually needed.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 9951dfd..11de1f1 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -808,7 +808,8 @@
struct tty_struct *tty;
unsigned long flags;
unsigned int status_idx = UART_STATE_INDEX;
- u8 prev_line_status;
+ u8 status;
+ u8 delta;
if (spriv->quirks & PL2303_QUIRK_UART_STATE_IDX0)
status_idx = 0;
@@ -816,24 +817,27 @@
if (actual_length < status_idx + 1)
return;
+ status = data[status_idx];
+
/* Save off the uart status for others to look at */
spin_lock_irqsave(&priv->lock, flags);
- prev_line_status = priv->line_status;
- priv->line_status = data[status_idx];
+ delta = priv->line_status ^ status;
+ priv->line_status = status;
spin_unlock_irqrestore(&priv->lock, flags);
- if (priv->line_status & UART_BREAK_ERROR)
+ if (status & UART_BREAK_ERROR)
usb_serial_handle_break(port);
wake_up_interruptible(&port->port.delta_msr_wait);
- tty = tty_port_tty_get(&port->port);
- if (!tty)
- return;
- if ((priv->line_status ^ prev_line_status) & UART_DCD)
- usb_serial_handle_dcd_change(port, tty,
- priv->line_status & UART_DCD);
- tty_kref_put(tty);
+ if (delta & UART_DCD) {
+ tty = tty_port_tty_get(&port->port);
+ if (tty) {
+ usb_serial_handle_dcd_change(port, tty,
+ status & UART_DCD);
+ tty_kref_put(tty);
+ }
+ }
}
static void pl2303_read_int_callback(struct urb *urb)