# Re: \[PATCH net\] net: hsr: enable promiscuous mode on interlink port with fwd offload

- From: Fernando Fernandez Mancera \<hidden\>
- Date: 2026-09-10 09:10:37 
- List: netdev
- Page: https://ratatoskr.run/netdev/2026/09/17544777
- Thread: https://ratatoskr.run/netdev/2026/09/17529554/t.md

```text
On 9/8/26 11:08 AM, MD Danish Anwar wrote:
> hsr_portdev_setup() skips promiscuous mode on non-master ports when
> hsr->fwd_offloaded is set. fwd_offloaded is derived only from the ring
> slaves' NETIF_F_HW_HSR_FWD bit, so this also skips it for the interlink
> port, which never gets forwarding offload. Without promiscuous mode,
> the interlink NIC drops unicast frames addressed to hsr_dev's MAC
> (e.g. SAN traffic to the RedBox), breaking RedBox whenever the ring is
> HW-offloaded.
>
> Fixes: 5055cccfc2d1 ("net: hsr: Provide RedBox support (HSR-SAN)")
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>

Reviewed-by: Fernando Fernandez Mancera <redacted>

Thanks!

> ---
>   net/hsr/hsr_slave.c | 11 +++++++----
>   1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
> index 01c73b4b50ddd..a546f70f9cc8b 100644
> --- a/net/hsr/hsr_slave.c
> +++ b/net/hsr/hsr_slave.c
> @@ -149,9 +149,12 @@ static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
>   	int res;
>   
>   	/* Don't use promiscuous mode for offload since L2 frame forward
> -	 * happens at the offloaded hardware.
> +	 * happens at the offloaded hardware. The interlink port never
> +	 * gets forwarding offload (RedBox forwarding to/from it is done
> +	 * by this driver), so it still needs promiscuous mode to receive
> +	 * frames addressed to hsr_dev's MAC rather than its own.
>   	 */
> -	if (!port->hsr->fwd_offloaded) {
> +	if (!port->hsr->fwd_offloaded || port->type == HSR_PT_INTERLINK) {
>   		res = dev_set_promiscuity(dev, 1);
>   		if (res)
>   			return res;
> @@ -176,7 +179,7 @@ static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
>   fail_rx_handler:
>   	netdev_upper_dev_unlink(dev, hsr_dev);
>   fail_upper_dev_link:
> -	if (!port->hsr->fwd_offloaded)
> +	if (!port->hsr->fwd_offloaded || port->type == HSR_PT_INTERLINK)
>   		dev_set_promiscuity(dev, -1);
>   
>   	return res;
> @@ -240,7 +243,7 @@ void hsr_del_port(struct hsr_port *port)
>   		netdev_update_features(master->dev);
>   		dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
>   		netdev_rx_handler_unregister(port->dev);
> -		if (!port->hsr->fwd_offloaded)
> +		if (!port->hsr->fwd_offloaded || port->type == HSR_PT_INTERLINK)
>   			dev_set_promiscuity(port->dev, -1);
>   		if (port->type == HSR_PT_SLAVE_A || port->type == HSR_PT_SLAVE_B)
>   			vlan_vids_del_by_dev(port->dev, master->dev);
>
> base-commit: 8d6cd188508513503805c156165de38e4e4a8615

```