usbnet: Get EVENT_NO_RUNTIME_PM bit before it is cleared

[ Upstream commit f50791ac1aca1ac1b0370d62397b43e9f831421a ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 3d50e7db141e9edfed1461720c732a18babcdefd..fb068ada0c5ad30a5464bbbc03b1676134b1d029 100644 (file)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -753,7 +753,7 @@ 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);
@@ -784,6 +784,8 @@ 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.
@@ -794,8 +796,7 @@ 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);