usbnet: Get EVENT_NO_RUNTIME_PM bit before it is cleared

It is needed to check EVENT_NO_RUNTIME_PM bit of dev->flags in
usbnet_stop(), but its value should be read before it is cleared
when dev->flags is set to 0.

The problem was spotted and the fix was provided by
Oliver Neukum <oneukum@suse.de>.

Signed-off-by: Eugene Shatokhin <eugene.shatokhin@rosalab.ru>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 3c86b107275a..e0498571ae26 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -778,7 +778,7 @@ int usbnet_stop (struct net_device *net)
 {
         struct usbnet           *dev = netdev_priv(net);
         struct driver_info      *info = dev->driver_info;
-        int                     retval, pm;
+        int                     retval, pm, mpn;
 
         clear_bit(EVENT_DEV_OPEN, &dev->flags);
         netif_stop_queue (net);
@@ -809,6 +809,8 @@ int usbnet_stop (struct net_device *net)
 
         usbnet_purge_paused_rxq(dev);
 
+        mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
+
         /* deferred work (task, timer, softirq) must also stop.
          * can't flush_scheduled_work() until we drop rtnl (later),
          * else workers could deadlock; so make workers a NOP.
@@ -819,8 +821,7 @@ int usbnet_stop (struct net_device *net)
         if (!pm)
                 usb_autopm_put_interface(dev->intf);
 
-        if (info->manage_power &&
-            !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
+        if (info->manage_power && mpn)
                 info->manage_power(dev, 0);
         else
                 usb_autopm_put_interface(dev->intf);