USB: serial: enable async suspend for usb serial port device

Usb serial port device is child of its usb interface device, so
we can enable async suspend of usb serial port device to speedup
system suspend.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 443468e9d66e015722b3b2baeda9317a0b6ecd84..2a982e62963b5b76a7bd894c412690b1ddb9381d 100644 (file)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -1071,6 +1071,8 @@ int usb_serial_probe(struct usb_interface *interface,
                dev_set_name(&port->dev, "ttyUSB%d", port->number);
                dbg ("%s - registering %s", __func__, dev_name(&port->dev));
                port->dev_state = PORT_REGISTERING;
+               device_enable_async_suspend(&port->dev);
+
                retval = device_add(&port->dev);
                if (retval) {
                        dev_err(&port->dev, "Error registering port device, "