Commit 62507e38 authored by Alexander Sverdlin's avatar Alexander Sverdlin Committed by Jakub Kicinski
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net: ethernet: ti: am65-cpsw: VLAN-aware CPSW only if !DSA 

Only configure VLAN-aware CPSW mode if no port is used as DSA CPU port.
VLAN-aware mode interferes with some DSA tagging schemes and makes stacking
DSA switches downstream of CPSW impossible. Previous attempts to address
the issue linked below.

Link: https://lore.kernel.org/netdev/20240227082815.2073826-1-s-vadapalli@ti.com/
Link: https://lore.kernel.org/linux-arm-kernel/4699400.vD3TdgH1nR@localhost/


Co-developed-by: default avatarSiddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: default avatarSiddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: default avatarAlexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://patch.msgid.link/20250110125737.546184-1-alexander.sverdlin@siemens.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b1b5cff6

drivers/net/ethernet/ti/am65-cpsw-nuss.c

+10 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <linux/dma/ti-cppi5.h>

#include <linux/dma/k3-udma-glue.h>

#include <net/page_pool/helpers.h>

#include <net/dsa.h>

#include <net/switchdev.h>



#include "cpsw_ale.h"
@@ -1014,6 +1015,15 @@ static int am65_cpsw_nuss_ndo_slave_open(struct net_device *ndev) 


	common->usage_count++;



	/* VLAN aware CPSW mode is incompatible with some DSA tagging schemes.

	 * Therefore disable VLAN_AWARE mode if any of the ports is a DSA Port.

	 */

	if (netdev_uses_dsa(ndev)) {

		reg = readl(common->cpsw_base + AM65_CPSW_REG_CTL);

		reg &= ~AM65_CPSW_CTL_VLAN_AWARE;

		writel(reg, common->cpsw_base + AM65_CPSW_REG_CTL);

	}



	am65_cpsw_port_set_sl_mac(port, ndev->dev_addr);

	am65_cpsw_port_enable_dscp_map(port);