[PATCH net-next 5/5] dpaa2-switch: fix handling of NAPI on the remove path

[Ioana Ciornei]

All the NAPI instances for a DPSW device are attached to the first
switch port's net_device but shared by all ports. The NAPI instances get
disabled only once the last port goes down.

This causes an issue on the .remove() path where each port is
unregistered and freed one at a time, causing the NAPI instances to be
deleted even though they are not disabled.

In order to avoid this, split up the unregister_netdev() calls from the
free_netdev() so that we make sure all ports go down before we attempt
a deletion of NAPI instances. Also, make the netif_napi_del() explicit
as it is on the .probe() path.

Signed-off-by: Ioana Ciornei <ioana.ciornei@xxxxxxx>
---
 .../net/ethernet/freescale/dpaa2/dpaa2-switch.c   | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index 505ccaa93ee4..a0bf5b50aae5 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -3304,7 +3304,6 @@ static void dpaa2_switch_teardown(struct fsl_mc_device *sw_dev)
 
 static void dpaa2_switch_remove(struct fsl_mc_device *sw_dev)
 {
-	struct ethsw_port_priv *port_priv;
 	struct ethsw_core *ethsw;
 	struct device *dev;
 	int i;
@@ -3316,11 +3315,17 @@ static void dpaa2_switch_remove(struct fsl_mc_device *sw_dev)
 
 	dpsw_disable(ethsw->mc_io, 0, ethsw->dpsw_handle);
 
-	for (i = 0; i < ethsw->sw_attr.num_ifs; i++) {
-		port_priv = ethsw->ports[i];
-		unregister_netdev(port_priv->netdev);
+	/* Unregister all the netdevs so that they are brought down and the
+	 * shared NAPI instances gets disabled.
+	 */
+	for (i = 0; i < ethsw->sw_attr.num_ifs; i++)
+		unregister_netdev(ethsw->ports[i]->netdev);
+
+	for (i = 0; i < DPAA2_SWITCH_RX_NUM_FQS; i++)
+		netif_napi_del(&ethsw->fq[i].napi);
+
+	for (i = 0; i < ethsw->sw_attr.num_ifs; i++)
 		dpaa2_switch_remove_port(ethsw, i);
-	}
 
 	kfree(ethsw->fdbs);
 	kfree(ethsw->filter_blocks);
-- 
2.25.1