net: dsa: lantiq_gswip: do also enable or disable cpu port

Before commit 74be4ba ("net: dsa: do not enable or disable non user
ports"), gswip_port_enable/disable() were also executed for the cpu port
in gswip_setup() which disabled the cpu port during initialization.

Let's restore this by removing the dsa_is_user_port checks. Also, let's
clean up the gswip_port_enable() function so that we only have to check
for the cpu port once. The operation reordering done here is safe.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20240611135434.3180973-7-ms@dev.tdt.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/lantiq_gswip.c

@@ -695,13 +695,18 @@ static int gswip_port_enable(struct dsa_switch *ds, int port,
 	struct gswip_priv *priv = ds->priv;
 	int err;
 
-	if (!dsa_is_user_port(ds, port))
-		return 0;
-
 	if (!dsa_is_cpu_port(ds, port)) {
+		u32 mdio_phy = 0;
+
 		err = gswip_add_single_port_br(priv, port, true);
 		if (err)
 			return err;
+
+		if (phydev)
+			mdio_phy = phydev->mdio.addr & GSWIP_MDIO_PHY_ADDR_MASK;
+
+		gswip_mdio_mask(priv, GSWIP_MDIO_PHY_ADDR_MASK, mdio_phy,
+				GSWIP_MDIO_PHYp(port));
 	}
 
 	/* RMON Counter Enable for port */
@@ -714,26 +719,13 @@ static int gswip_port_enable(struct dsa_switch *ds, int port,
 	gswip_switch_mask(priv, 0, GSWIP_SDMA_PCTRL_EN,
 			  GSWIP_SDMA_PCTRLp(port));
 
-	if (!dsa_is_cpu_port(ds, port)) {
-		u32 mdio_phy = 0;
-
-		if (phydev)
-			mdio_phy = phydev->mdio.addr & GSWIP_MDIO_PHY_ADDR_MASK;
-
-		gswip_mdio_mask(priv, GSWIP_MDIO_PHY_ADDR_MASK, mdio_phy,
-				GSWIP_MDIO_PHYp(port));
-	}
-
 	return 0;
 }
 
 static void gswip_port_disable(struct dsa_switch *ds, int port)
 {
 	struct gswip_priv *priv = ds->priv;
 
-	if (!dsa_is_user_port(ds, port))
-		return;
-
 	gswip_switch_mask(priv, GSWIP_FDMA_PCTRL_EN, 0,
 			  GSWIP_FDMA_PCTRLp(port));
 	gswip_switch_mask(priv, GSWIP_SDMA_PCTRL_EN, 0,