[PATCH net] net: ti: icssg-prueth: Fix switch mode for offload and non-offload cases

[PATCH net] net: ti: icssg-prueth: Fix switch mode for offload and non-offload cases

[Meghana Malladi]

Non-offloaded switch mode is failing to forward packets. Following fixes
ensure smooth operation of switch mode in both offload and non-offload cases:

- Fix NULL dereference in icssg_enable_fw_offload() when second emac
  slot is uninitialized during first port open
- Set port_vlan on both emacs when bridge is formed; previously only
  the second port was set, causing TX stalls in switch offload mode
- Track UC/MC flooding state and restore it after firmware restart in
  non-offload bridge mode; restart cleared IFF_PROMISC-driven flooding,
  breaking unicast forwarding across bridge ports
- Defer emac_adjust_link() to after prueth_emac_start() so R30 FORWARD
  commands don't time out with PRU not running, leaving stale R30 values
  that caused prueth_emac_restart() to fail in non-offload bridge mode

Fixes: 161087db66d6b ("net: ti: icssg-prueth: Add Support for Multicast filtering with VLAN in HSR mode")
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
---
 drivers/net/ethernet/ti/icssg/icssg_prueth.c | 47 +++++++++++++++-----
 drivers/net/ethernet/ti/icssg/icssg_prueth.h |  4 ++
 2 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
index 591be5c8056b..9afda5da3ca3 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
@@ -213,6 +213,8 @@ static void icssg_enable_fw_offload(struct prueth *prueth)
 
 	for (mac = PRUETH_MAC0; mac < PRUETH_NUM_MACS; mac++) {
 		emac = prueth->emac[mac];
+		if (!emac)
+			continue;
 		if (prueth->is_hsr_offload_mode) {
 			if (emac->ndev->features & NETIF_F_HW_HSR_TAG_RM)
 				icssg_set_port_state(emac, ICSSG_EMAC_HSR_RX_OFFLOAD_ENABLE);
@@ -241,6 +243,16 @@ static void icssg_enable_fw_offload(struct prueth *prueth)
 					icssg_set_port_state(emac, ICSSG_EMAC_PORT_VLAN_AWARE_ENABLE);
 			}
 		}
+
+		/* Re-apply flooding state cleared by firmware restart.
+		 * Not needed in switch mode; FDB handles forwarding there.
+		 */
+		if (!prueth->is_switch_mode && netif_running(emac->ndev)) {
+			if (emac->uc_flooding_enabled)
+				icssg_set_port_state(emac, ICSSG_EMAC_PORT_UC_FLOODING_ENABLE);
+			if (emac->mc_flooding_enabled)
+				icssg_set_port_state(emac, ICSSG_EMAC_PORT_MC_FLOODING_ENABLE);
+		}
 	}
 }
 
@@ -278,13 +290,22 @@ static int prueth_emac_common_start(struct prueth *prueth)
 		ret = icssg_config(prueth, emac, slice);
 		if (ret)
 			goto disable_class;
+	}
+
+	ret = prueth_emac_start(prueth);
+	if (ret)
+		goto disable_class;
+
+	/* Reset link state and reconfigure after firmware is running.
+	 * Must be done after prueth_emac_start() so that R30 commands
+	 * (e.g. ICSSG_EMAC_PORT_FORWARD from emac_adjust_link) reach
+	 * the PRU firmware instead of timing out with stale R30 values.
+	 */
+	for (slice = 0; slice < PRUETH_NUM_MACS; slice++) {
+		emac = prueth->emac[slice];
+		if (!emac)
+			continue;
 
-		/* Reset link state to force reconfiguration in
-		 * emac_adjust_link(). Without this, if the link was already up
-		 * before restart, emac_adjust_link() won't detect any state
-		 * change and will skip critical configuration like writing
-		 * speed to firmware.
-		 */
 		emac->link = 0;
 
 		mutex_lock(&emac->ndev->phydev->lock);
@@ -292,10 +313,6 @@ static int prueth_emac_common_start(struct prueth *prueth)
 		mutex_unlock(&emac->ndev->phydev->lock);
 	}
 
-	ret = prueth_emac_start(prueth);
-	if (ret)
-		goto disable_class;
-
 	emac = prueth->emac[ICSS_SLICE0] ? prueth->emac[ICSS_SLICE0] :
 	       prueth->emac[ICSS_SLICE1];
 	ret = icss_iep_init(emac->iep, &prueth_iep_clockops,
@@ -1288,14 +1305,21 @@ static void emac_ndo_set_rx_mode_work(struct work_struct *work)
 	if (promisc) {
 		icssg_set_port_state(emac, ICSSG_EMAC_PORT_UC_FLOODING_ENABLE);
 		icssg_set_port_state(emac, ICSSG_EMAC_PORT_MC_FLOODING_ENABLE);
+		emac->uc_flooding_enabled = true;
+		emac->mc_flooding_enabled = true;
 		return;
 	}
 
 	if (allmulti) {
 		icssg_set_port_state(emac, ICSSG_EMAC_PORT_MC_FLOODING_ENABLE);
+		emac->mc_flooding_enabled = true;
+		emac->uc_flooding_enabled = false;
 		return;
 	}
 
+	emac->uc_flooding_enabled = false;
+	emac->mc_flooding_enabled = false;
+
 	if (emac->prueth->is_hsr_offload_mode) {
 		/* Track basic add/delete via callbacks */
 		__dev_mc_sync(ndev, icssg_prueth_hsr_add_mcast,
@@ -1919,7 +1943,8 @@ static int prueth_netdevice_port_link(struct net_device *ndev,
 		    prueth->br_members & BIT(PRUETH_PORT_MII1)) {
 			prueth->is_switch_mode = true;
 			prueth->default_vlan = PRUETH_DFLT_VLAN_SW;
-			emac->port_vlan = prueth->default_vlan;
+			prueth->emac[PRUETH_MAC0]->port_vlan = prueth->default_vlan;
+			prueth->emac[PRUETH_MAC1]->port_vlan = prueth->default_vlan;
 			icssg_change_mode(prueth);
 		}
 	}
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index df93d15c5b78..832e654a102c 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -242,6 +242,10 @@ struct prueth_emac {
 	bool offload_fwd_mark;
 	int port_vlan;
 
+	/* UC/MC flooding state - preserved across firmware restarts */
+	unsigned int uc_flooding_enabled : 1;
+	unsigned int mc_flooding_enabled : 1;
+
 	struct delayed_work stats_work;
 	u64 stats[ICSSG_NUM_MIIG_STATS];
 	u64 pa_stats[ICSSG_NUM_PA_STATS];

base-commit: 99b43ede9e355ba35244cc9470bf1819774ce39d
-- 
2.43.0

Re: [PATCH net] net: ti: icssg-prueth: Fix switch mode for offload and non-offload cases

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - What hardware the change was tested on. For driver fixes please
   mention the device (and if relevant firmware version) used for
   testing, or say that the change was not tested on real hardware.

Please do not repost the series just to address the above. Instead,
reply to this email with the missing information, so that reviewers
can take it into account. If the series needs another revision for
other reasons, please include the information in the commit messages
then.

The evaluation is done by an LLM so it may be wrong, if you think
that is the case please reply and explain.

Re: [PATCH net] net: ti: icssg-prueth: Fix switch mode for offload and non-offload cases

[Andrew Lunn]

On Wed, Sep 30, 2026 at 06:13:56PM +0530, Meghana Malladi wrote:
> Non-offloaded switch mode is failing to forward packets. Following fixes
> ensure smooth operation of switch mode in both offload and non-offload cases:
> 
> - Fix NULL dereference in icssg_enable_fw_offload() when second emac
>   slot is uninitialized during first port open
> - Set port_vlan on both emacs when bridge is formed; previously only
>   the second port was set, causing TX stalls in switch offload mode
> - Track UC/MC flooding state and restore it after firmware restart in
>   non-offload bridge mode; restart cleared IFF_PROMISC-driven flooding,
>   breaking unicast forwarding across bridge ports
> - Defer emac_adjust_link() to after prueth_emac_start() so R30 FORWARD
>   commands don't time out with PRU not running, leaving stale R30 values
>   that caused prueth_emac_restart() to fail in non-offload bridge mode

A bullet point list in the commit message suggests there should be a
patch series of patches, not one patch. You want small, obviously
correct patches with good commit messages.


    Andrew

---
pw-bot: cr