Adding upstream version 4.19.282.upstream/4.19.282

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 18 insertions, 1 deletions

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 41e32a958..08f0da9e6 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -136,6 +136,20 @@ static void queue_process(struct work_struct *work)
 	}
 }
 
+static int netif_local_xmit_active(struct net_device *dev)
+{
+	int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+
+		if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id())
+			return 1;
+	}
+
+	return 0;
+}
+
 static void poll_one_napi(struct napi_struct *napi)
 {
 	int work;
@@ -182,7 +196,10 @@ void netpoll_poll_dev(struct net_device *dev)
 	if (!ni || down_trylock(&ni->dev_lock))
 		return;
 
-	if (!netif_running(dev)) {
+	/* Some drivers will take the same locks in poll and xmit,
+	 * we can't poll if local CPU is already in xmit.
+	 */
+	if (!netif_running(dev) || netif_local_xmit_active(dev)) {
 		up(&ni->dev_lock);
 		return;
 	}