When stopping the port, the CPU notifier are still there whereas the
mvneta_stop_dev function calls mvneta_percpu_disable() on each CPUs.
It was possible to have a new CPU coming at this point which could be
racy.
This patch adds a flag preventing executing the code notifier for a new CPU
when the port is stopping.
Signed-off-by: Gregory CLEMENT <gregory.clem...@free-electrons.com>
---
drivers/net/ethernet/marvell/mvneta.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/net/ethernet/marvell/mvneta.c
b/drivers/net/ethernet/marvell/mvneta.c
index 3358c9a70467..22962fac47c2 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -372,6 +372,7 @@ struct mvneta_port {
int rxq_def;
/* protect */
spinlock_t lock;
+ bool is_stopping;
/* Core clock */
struct clk *clk;
@@ -2914,6 +2915,11 @@ static int mvneta_percpu_notifier(struct notifier_block
*nfb,
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
+ /* Configuring the driver for a new CPU while the
+ * driver is stopping is racy, so just avoid it.
+ */
+ if (pp->is_stopping)
+ break;
netif_tx_stop_all_queues(pp->dev);
/* We have to synchronise on tha napi of each CPU
@@ -3052,9 +3058,17 @@ static int mvneta_stop(struct net_device *dev)
{
struct mvneta_port *pp = netdev_priv(dev);
+ /* Inform that we are stopping so we don't want to setup the
+ * driver for new CPUs in the notifiers
+ */
+ pp->is_stopping = true;
mvneta_stop_dev(pp);
mvneta_mdio_remove(pp);
unregister_cpu_notifier(&pp->cpu_notifier);
+ /* Now that the notifier are unregistered, we can clear the
+ * flag
+ */
+ pp->is_stopping = false;
on_each_cpu(mvneta_percpu_disable, pp, true);
free_percpu_irq(dev->irq, pp->ports);
mvneta_cleanup_rxqs(pp);
--
2.5.0
