USB: cdc-acm: do not update PM busy on read errors

There's no need to update the runtime PM last_busy field on read urb
errors (e.g. when the urb is being killed on shutdown).

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index f038f39..3c7cfac 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -416,13 +416,15 @@ static void acm_read_bulk_callback(struct urb *urb)
                dev_dbg(&acm->data->dev, "%s - disconnected\n", __func__);
                return;
        }
-       usb_mark_last_busy(acm->dev);
 
        if (urb->status) {
                dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
                                                        __func__, urb->status);
                return;
        }
+
+       usb_mark_last_busy(acm->dev);
+
        acm_process_read_urb(acm, urb);
 
        /* throttle device if requested by tty */