USB: option: fix runtime PM handling

Fix potential I/O while runtime suspended due to missing PM operations
in send_setup.

Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the
option driver")

Cc: <stable@vger.kernel.org>        # v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index f213ee9..802c069 100644 (file)
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -1923,6 +1923,7 @@ static int option_send_setup(struct usb_serial_port *port)
        struct option_private *priv = intfdata->private;
        struct usb_wwan_port_private *portdata;
        int val = 0;
+       int res;
 
        portdata = usb_get_serial_port_data(port);
 
@@ -1931,9 +1932,17 @@ static int option_send_setup(struct usb_serial_port *port)
        if (portdata->rts_state)
                val |= 0x02;
 
-       return usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+       res = usb_autopm_get_interface(serial->interface);
+       if (res)
+               return res;
+
+       res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
                                0x22, 0x21, val, priv->bInterfaceNumber, NULL,
                                0, USB_CTRL_SET_TIMEOUT);
+
+       usb_autopm_put_interface(serial->interface);
+
+       return res;
 }
 
 MODULE_AUTHOR(DRIVER_AUTHOR);