From: Edwin Peer edwin.peer@broadcom.com
commit 3aa6bce9af0e25b735c9c1263739a5639a336ae8 upstream.
Prevent netif_tx_disable() running concurrently with dev_watchdog() by taking the device global xmit lock. Otherwise, the recommended:
netif_carrier_off(dev); netif_tx_disable(dev);
driver shutdown sequence can happen after the watchdog has already checked carrier, resulting in possible false alarms. This is because netif_tx_lock() only sets the frozen bit without maintaining the locks on the individual queues.
Fixes: c3f26a269c24 ("netdev: Fix lockdep warnings in multiqueue configurations.") Signed-off-by: Edwin Peer edwin.peer@broadcom.com Reviewed-by: Jakub Kicinski kuba@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/netdevice.h | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 2b1197c83a5ec..61ad607027f3e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4097,6 +4097,7 @@ static inline void netif_tx_disable(struct net_device *dev)
local_bh_disable(); cpu = smp_processor_id(); + spin_lock(&dev->tx_global_lock); for (i = 0; i < dev->num_tx_queues; i++) { struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
@@ -4104,6 +4105,7 @@ static inline void netif_tx_disable(struct net_device *dev) netif_tx_stop_queue(txq); __netif_tx_unlock(txq); } + spin_unlock(&dev->tx_global_lock); local_bh_enable(); }