Re: [RFC PATCH net-next 04/16] net: mscc: ocelot: use a switch-case statement in ocelot_netdevice_event

On 15/12/2020 16:52:26+0100, Alexandre Belloni wrote:

On 08/12/2020 14:07:50+0200, Vladimir Oltean wrote:

quoted

Make ocelot's net device event handler more streamlined by structuring
it in a similar way with others. The inspiration here was
dsa_slave_netdevice_event.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 drivers/net/ethernet/mscc/ocelot_net.c | 68 +++++++++++++++++---------
 1 file changed, 45 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 50765a3b1c44..47b620967156 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c

@@ -1030,49 +1030,71 @@ static int ocelot_netdevice_changeupper(struct net_device *dev,
 					      info->upper_dev);
 	}
 
-	return err;
+	return notifier_from_errno(err);
+}
+
+static int
+ocelot_netdevice_lag_changeupper(struct net_device *dev,
+				 struct netdev_notifier_changeupper_info *info)
+{
+	struct net_device *lower;
+	struct list_head *iter;
+	int err = NOTIFY_DONE;
+
+	netdev_for_each_lower_dev(dev, lower, iter) {
+		err = ocelot_netdevice_changeupper(lower, info);
+		if (err)
+			return notifier_from_errno(err);
+	}
+
+	return NOTIFY_DONE;
 }
 
 static int ocelot_netdevice_event(struct notifier_block *unused,
 				  unsigned long event, void *ptr)
 {
-	struct netdev_notifier_changeupper_info *info = ptr;
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-	int ret = 0;
 
-	if (event == NETDEV_PRECHANGEUPPER &&
-	    ocelot_netdevice_dev_check(dev) &&
-	    netif_is_lag_master(info->upper_dev)) {
-		struct netdev_lag_upper_info *lag_upper_info = info->upper_info;
+	switch (event) {
+	case NETDEV_PRECHANGEUPPER: {
+		struct netdev_notifier_changeupper_info *info = ptr;
+		struct netdev_lag_upper_info *lag_upper_info;
 		struct netlink_ext_ack *extack;
 
+		if (!ocelot_netdevice_dev_check(dev))
+			break;
+
+		if (!netif_is_lag_master(info->upper_dev))
+			break;
+
+		lag_upper_info = info->upper_info;
+
 		if (lag_upper_info &&
 		    lag_upper_info->tx_type != NETDEV_LAG_TX_TYPE_HASH) {
 			extack = netdev_notifier_info_to_extack(&info->info);
 			NL_SET_ERR_MSG_MOD(extack, "LAG device using unsupported Tx type");
 
-			ret = -EINVAL;
-			goto notify;
+			return NOTIFY_BAD;

This changes the return value in case of error, I'm not sure how
important this is.

Ok, this is removed anyway, so

Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

quoted

 		}
+
+		break;
 	}
+	case NETDEV_CHANGEUPPER: {
+		struct netdev_notifier_changeupper_info *info = ptr;
 
-	if (event == NETDEV_CHANGEUPPER) {
-		if (netif_is_lag_master(dev)) {
-			struct net_device *slave;
-			struct list_head *iter;
+		if (ocelot_netdevice_dev_check(dev))
+			return ocelot_netdevice_changeupper(dev, info);
 
-			netdev_for_each_lower_dev(dev, slave, iter) {
-				ret = ocelot_netdevice_changeupper(slave, event, info);
-				if (ret)
-					goto notify;
-			}
-		} else {
-			ret = ocelot_netdevice_changeupper(dev, event, info);
-		}
+		if (netif_is_lag_master(dev))
+			return ocelot_netdevice_lag_changeupper(dev, info);
+
+		break;
+	}
+	default:
+		break;
 	}
 
-notify:
-	return notifier_from_errno(ret);
+	return NOTIFY_DONE;

This changes the return value from NOTIFY_OK to NOTIFY_DONE but this is
probably what we want.

quoted

 }
 
 struct notifier_block ocelot_netdevice_nb __read_mostly = {
-- 
2.25.1

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com