[PATCH net] hsr: use netdev_master_upper_dev_link() when linking lower ports

[PATCH net] hsr: use netdev_master_upper_dev_link() when linking lower ports

[Hangbin Liu]

Unlike VLAN devices, HSR changes the lower device’s rx_handler, which
prevents the lower device from being attached to another master.
Switch to using netdev_master_upper_dev_link() when setting up the lower
device.

This also improves user experience, since ip link will now display the
HSR device as the master for its ports.

Fixes: e0a4b99773d3 ("hsr: use upper/lower device infrastructure")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 net/hsr/hsr_slave.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
index 102eccf5ead7..8177ac6c2d26 100644
--- a/net/hsr/hsr_slave.c
+++ b/net/hsr/hsr_slave.c
@@ -143,6 +143,7 @@ static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
 			     struct netlink_ext_ack *extack)
 
 {
+	struct netdev_lag_upper_info lag_upper_info;
 	struct net_device *hsr_dev;
 	struct hsr_port *master;
 	int res;
@@ -159,7 +160,9 @@ static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
 	hsr_dev = master->dev;
 
-	res = netdev_upper_dev_link(dev, hsr_dev, extack);
+	lag_upper_info.tx_type = NETDEV_LAG_TX_TYPE_BROADCAST;
+	lag_upper_info.hash_type = NETDEV_LAG_HASH_UNKNOWN;
+	res = netdev_master_upper_dev_link(dev, hsr_dev, NULL, &lag_upper_info, extack);
 	if (res)
 		goto fail_upper_dev_link;
 
-- 
2.50.1

Re: [PATCH net] hsr: use netdev_master_upper_dev_link() when linking lower ports

[Jakub Kicinski]

On Tue, 26 Aug 2025 01:33:52 +0000 Hangbin Liu wrote:
> Unlike VLAN devices, HSR changes the lower device’s rx_handler, which
> prevents the lower device from being attached to another master.
> Switch to using netdev_master_upper_dev_link() when setting up the lower
> device.
> 
> This also improves user experience, since ip link will now display the
       ^^^^

Why this "also" here? You haven't mentioned any benefit of this change
up to this point. AFAIK having the master link is the only one?

> HSR device as the master for its ports.
> 
> Fixes: e0a4b99773d3 ("hsr: use upper/lower device infrastructure")

The current behavior is 5 years old, AFAICT. We need a reason to treat
this as a fix, right now this looks like net-next material..
-- 
pw-bot: cr

Re: [PATCH net] hsr: use netdev_master_upper_dev_link() when linking lower ports

[Hangbin Liu]

On Wed, Aug 27, 2025 at 06:06:03PM -0700, Jakub Kicinski wrote:
> On Tue, 26 Aug 2025 01:33:52 +0000 Hangbin Liu wrote:
> > Unlike VLAN devices, HSR changes the lower device’s rx_handler, which
> > prevents the lower device from being attached to another master.
> > Switch to using netdev_master_upper_dev_link() when setting up the lower
> > device.
> > 
> > This also improves user experience, since ip link will now display the
>        ^^^^
> 
> Why this "also" here? You haven't mentioned any benefit of this change
> up to this point. AFAIK having the master link is the only one?

Apart from the "fix"(I thought), we can "also" benefit of the ip link output.

> 
> > HSR device as the master for its ports.
> > 
> > Fixes: e0a4b99773d3 ("hsr: use upper/lower device infrastructure")
> 
> The current behavior is 5 years old, AFAICT. We need a reason to treat
> this as a fix, right now this looks like net-next material..

If you think this is not a fix. Sure I can remove the "also" word and post to
net-next :)

Thanks
Hangbin