net: Fix issue with netdev_tx_reset_queue not resetting queue from XOFF state

[ Upstream commit 5c4903549c05bbb373479e0ce2992573c120654a ]

We are seeing dev_watchdog hangs on several drivers.  I suspect this is due
to the __QUEUE_STATE_STACK_XOFF bit being set prior to a reset for link
change, and then not being cleared by netdev_tx_reset_queue.  This change
corrects that.

In addition we were seeing dev_watchdog hangs on igb after running the
ethtool tests.  We found this to be due to the fact that the ethtool test
runs the same logic as ndo_start_xmit, but we were never clearing the XOFF
flag since the loopback test in ethtool does not do byte queue accounting.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Stephen Ko <stephen.s.ko@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ebf598097890c4365a0cb38bb83d44b04e344d60..7e472b737d7dec8bb59fb27b8d7ff5646be45c96 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1955,6 +1955,7 @@ static inline void netdev_completed_queue(struct net_device *dev,
 static inline void netdev_tx_reset_queue(struct netdev_queue *q)
 {
 #ifdef CONFIG_BQL
+       clear_bit(__QUEUE_STATE_STACK_XOFF, &q->state);
        dql_reset(&q->dql);
 #endif
 }