--- /dev/null
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Fri, 27 Feb 2026 19:59:16 +0100
+Subject: [PATCH] net: dsa: b53: disable EAP setup on Northstar switches
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+It breaks standalone ports.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+---
+ drivers/net/dsa/b53/b53_common.c | 15 +++++++++++++++
+ 1 file changed, 15 insertions(+)
+
+--- a/drivers/net/dsa/b53/b53_common.c
++++ b/drivers/net/dsa/b53/b53_common.c
+@@ -332,6 +332,21 @@ static void b53_set_eap_mode(struct b53_
+ {
+ u64 eap_conf;
+
++ /*
++ * On Northstar devices (SoCs with BCM53011 / BCM53012) setting
++ * EAP_MODE_SIMPLIFIED breaks standalone ports.
++ *
++ * See:
++ * https://lore.kernel.org/netdev/ce4d9b7b-aaf6-4796-94fb-8c3d6a1dcd4d@gmail.com/
++ * https://github.com/openwrt/openwrt/issues/21187
++ * https://github.com/openwrt/openwrt/issues/21349
++ *
++ * For details on EAP see commit 4227ea91e265 ("net: dsa: b53: prevent
++ * standalone from trying to forward to other ports").
++ */
++ if (is5301x(dev))
++ return;
++
+ if (is5325(dev) || is5365(dev) || dev->chip_id == BCM5389_DEVICE_ID)
+ return;
+