net: dsa: b53: do not set learning and unicast/multicast on up

BugLink: https://bugs.launchpad.net/bugs/2130277

[ Upstream commit 2e7179c ]

When a port gets set up, b53 disables learning and enables the port for
flooding. This can undo any bridge configuration on the port.

E.g. the following flow would disable learning on a port:

$ ip link add br0 type bridge
$ ip link set sw1p1 master br0 <- enables learning for sw1p1
$ ip link set br0 up
$ ip link set sw1p1 up <- disables learning again

Fix this by populating dsa_switch_ops::port_setup(), and set up initial
config there.

Fixes: f9b3827 ("net: dsa: b53: Support setting learning on port")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250429201710.330937-12-jonas.gorski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

Author: KanjiMonster

drivers/net/dsa/b53/b53_common.c

@@ -565,6 +565,18 @@ static void b53_port_set_learning(struct b53_device *dev, int port,
 	b53_write16(dev, B53_CTRL_PAGE, B53_DIS_LEARNING, reg);
 }
 
+int b53_setup_port(struct dsa_switch *ds, int port)
+{
+	struct b53_device *dev = ds->priv;
+
+	b53_port_set_ucast_flood(dev, port, true);
+	b53_port_set_mcast_flood(dev, port, true);
+	b53_port_set_learning(dev, port, false);
+
+	return 0;
+}
+EXPORT_SYMBOL(b53_setup_port);
+
 int b53_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy)
 {
 	struct b53_device *dev = ds->priv;
@@ -577,10 +589,6 @@ int b53_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy)
 
 	cpu_port = dsa_to_port(ds, port)->cpu_dp->index;
 
-	b53_port_set_ucast_flood(dev, port, true);
-	b53_port_set_mcast_flood(dev, port, true);
-	b53_port_set_learning(dev, port, false);
-
 	if (dev->ops->irq_enable)
 		ret = dev->ops->irq_enable(dev, port);
 	if (ret)
@@ -711,10 +719,6 @@ static void b53_enable_cpu_port(struct b53_device *dev, int port)
 	b53_write8(dev, B53_CTRL_PAGE, B53_PORT_CTRL(port), port_ctrl);
 
 	b53_brcm_hdr_setup(dev->ds, port);
-
-	b53_port_set_ucast_flood(dev, port, true);
-	b53_port_set_mcast_flood(dev, port, true);
-	b53_port_set_learning(dev, port, false);
 }
 
 static void b53_enable_mib(struct b53_device *dev)
@@ -2396,6 +2400,7 @@ static const struct dsa_switch_ops b53_switch_ops = {
 	.phylink_mac_config	= b53_phylink_mac_config,
 	.phylink_mac_link_down	= b53_phylink_mac_link_down,
 	.phylink_mac_link_up	= b53_phylink_mac_link_up,
+	.port_setup		= b53_setup_port,
 	.port_enable		= b53_enable_port,
 	.port_disable		= b53_disable_port,
 	.get_mac_eee		= b53_get_mac_eee,

drivers/net/dsa/b53/b53_priv.h

@@ -394,6 +394,7 @@ enum dsa_tag_protocol b53_get_tag_protocol(struct dsa_switch *ds, int port,
 					   enum dsa_tag_protocol mprot);
 void b53_mirror_del(struct dsa_switch *ds, int port,
 		    struct dsa_mall_mirror_tc_entry *mirror);
+int b53_setup_port(struct dsa_switch *ds, int port);
 int b53_enable_port(struct dsa_switch *ds, int port, struct phy_device *phy);
 void b53_disable_port(struct dsa_switch *ds, int port);
 void b53_brcm_hdr_setup(struct dsa_switch *ds, int port);

drivers/net/dsa/bcm_sf2.c

@@ -1216,6 +1216,7 @@ static const struct dsa_switch_ops bcm_sf2_ops = {
 	.resume			= bcm_sf2_sw_resume,
 	.get_wol		= bcm_sf2_sw_get_wol,
 	.set_wol		= bcm_sf2_sw_set_wol,
+	.port_setup		= b53_setup_port,
 	.port_enable		= bcm_sf2_port_setup,
 	.port_disable		= bcm_sf2_port_disable,
 	.get_mac_eee		= b53_get_mac_eee,