Re: [PATCH net] net: bcmgenet: restore the hardware filters on open

From: Nicolai Buchwitz <nb@tipi-net.de>

bcmgenet_hfb_init() runs INIT_LIST_HEAD() on priv->rxnfc_list, which drops
every rule off the list, and bcmgenet_open() calls it on each ifup. Every
rule the user configured is silently lost:

  # ethtool -N eth0 flow-type ether dst $MAC action 0
  Added rule with ID 0
  # ethtool -n eth0 | grep -c Filter:
  1
  # ip link set eth0 down && ip link set eth0 up
  # ethtool -n eth0 | grep -c Filter:
  0

Initialise the lists once at probe and restore the rules on open, as
bcmgenet_resume() already does.

Fixes: 3e370952287c ("net: bcmgenet: add support for ethtool rxnfc flows")
Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Justin Chen <justin.chen@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20260913190052.939955-1-nb@tipi-net.de (local)
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../net/ethernet/broadcom/genet/bcmgenet.c    | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index a2305e6428d1..b916080f4ff1 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c

@@ -749,8 +749,17 @@ static void bcmgenet_hfb_init(struct bcmgenet_priv *priv)
                INIT_LIST_HEAD(&priv->rxnfc_rules[i].list);
                priv->rxnfc_rules[i].state = BCMGENET_RXNFC_STATE_UNUSED;
        }
+}
+
+static void bcmgenet_hfb_restore(struct bcmgenet_priv *priv)
+{
+       struct bcmgenet_rxnfc_rule *rule;

        bcmgenet_hfb_clear(priv);
+
+       list_for_each_entry(rule, &priv->rxnfc_list, list)
+               if (rule->state != BCMGENET_RXNFC_STATE_UNUSED)
+                       bcmgenet_hfb_create_rxnfc_filter(priv, rule);
 }

 static int bcmgenet_begin(struct net_device *dev)

@@ -3376,8 +3385,8 @@ static int bcmgenet_open(struct net_device *dev)

        bcmgenet_set_hw_addr(priv, dev->dev_addr);

-       /* HFB init */
-       bcmgenet_hfb_init(priv);
+       /* Restore the filters, the MAC was reset above */
+       bcmgenet_hfb_restore(priv);

        /* Reinitialize TDMA and RDMA and SW housekeeping */
        ret = bcmgenet_init_dma(priv, true);

@@ -4075,6 +4084,7 @@ static int bcmgenet_probe(struct platform_device *pdev)

        /* Mii wait queue */
        init_waitqueue_head(&priv->wq);
+       bcmgenet_hfb_init(priv);
        INIT_WORK(&priv->bcmgenet_irq_work, bcmgenet_irq_task);

        priv->clk_wol = devm_clk_get_optional(&priv->pdev->dev, "enet-wol");

@@ -4272,10 +4282,7 @@ static int bcmgenet_resume(struct device *d)
        bcmgenet_set_hw_addr(priv, dev->dev_addr);

        /* Restore hardware filters */
-       bcmgenet_hfb_clear(priv);
-       list_for_each_entry(rule, &priv->rxnfc_list, list)
-               if (rule->state != BCMGENET_RXNFC_STATE_UNUSED)
-                       bcmgenet_hfb_create_rxnfc_filter(priv, rule);
+       bcmgenet_hfb_restore(priv);

        /* Reinitialize TDMA and RDMA and SW housekeeping */
        ret = bcmgenet_init_dma(priv, false);
--

2.43.0