net: stmmac: configure SerDes on mac_finish

SerDes will configure according to the provided interface mode after
finish a major reconfiguration of the interface mode.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>
Link: https://patch.msgid.link/20250227121522.1802832-5-yong.liang.choong@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -1129,6 +1129,18 @@ static int stmmac_mac_enable_tx_lpi(struct phylink_config *config, u32 timer,
 	return 0;
 }
 
+static int stmmac_mac_finish(struct phylink_config *config, unsigned int mode,
+			     phy_interface_t interface)
+{
+	struct net_device *ndev = to_net_dev(config->dev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+
+	if (priv->plat->mac_finish)
+		priv->plat->mac_finish(ndev, priv->plat->bsp_priv, mode, interface);
+
+	return 0;
+}
+
 static const struct phylink_mac_ops stmmac_phylink_mac_ops = {
 	.mac_get_caps = stmmac_mac_get_caps,
 	.mac_select_pcs = stmmac_mac_select_pcs,
@@ -1137,6 +1149,7 @@ static const struct phylink_mac_ops stmmac_phylink_mac_ops = {
 	.mac_link_up = stmmac_mac_link_up,
 	.mac_disable_tx_lpi = stmmac_mac_disable_tx_lpi,
 	.mac_enable_tx_lpi = stmmac_mac_enable_tx_lpi,
+	.mac_finish = stmmac_mac_finish,
 };
 
 /**

include/linux/stmmac.h

@@ -239,6 +239,10 @@ struct plat_stmmacenet_data {
 	int (*serdes_powerup)(struct net_device *ndev, void *priv);
 	void (*serdes_powerdown)(struct net_device *ndev, void *priv);
 	void (*speed_mode_2500)(struct net_device *ndev, void *priv);
+	int (*mac_finish)(struct net_device *ndev,
+			  void *priv,
+			  unsigned int mode,
+			  phy_interface_t interface);
 	void (*ptp_clk_freq_config)(struct stmmac_priv *priv);
 	int (*init)(struct platform_device *pdev, void *priv);
 	void (*exit)(struct platform_device *pdev, void *priv);