From: Revanth Kumar Uppala <ruppala@nvidia.com>
Date: Thu, 1 Dec 2022 15:58:43 +0000
Subject: net: stmmac: Power up SERDES after the PHY link
Git-commit: a46e9010124256f5bf5fc2c241a45cf1944b768e
Patch-mainline: v6.2-rc1
References: jsc#PED-1763

The Tegra MGBE ethernet controller requires that the SERDES link is
powered-up after the PHY link is up, otherwise the link fails to
become ready following a resume from suspend. Add a variable to indicate
that the SERDES link must be powered-up after the PHY link.

Signed-off-by: Revanth Kumar Uppala <ruppala@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |    7 +++++--
 include/linux/stmmac.h                            |    1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1084,6 +1084,9 @@ static void stmmac_mac_link_up(struct ph
 	struct stmmac_priv *priv = netdev_priv(to_net_dev(config->dev));
 	u32 old_ctrl, ctrl;
 
+	if (priv->plat->serdes_up_after_phy_linkup && priv->plat->serdes_powerup)
+		priv->plat->serdes_powerup(priv->dev, priv->plat->bsp_priv);
+
 	old_ctrl = readl(priv->ioaddr + MAC_CTRL_REG);
 	ctrl = old_ctrl & ~priv->hw->link.speed_mask;
 
@@ -3760,7 +3763,7 @@ static int stmmac_open(struct net_device
 		goto init_error;
 	}
 
-	if (priv->plat->serdes_powerup) {
+	if (!priv->plat->serdes_up_after_phy_linkup && priv->plat->serdes_powerup) {
 		ret = priv->plat->serdes_powerup(dev, priv->plat->bsp_priv);
 		if (ret < 0) {
 			netdev_err(priv->dev, "%s: Serdes powerup failed\n",
@@ -7446,7 +7449,7 @@ int stmmac_resume(struct device *dev)
 			stmmac_mdio_reset(priv->mii);
 	}
 
-	if (priv->plat->serdes_powerup) {
+	if (!priv->plat->serdes_up_after_phy_linkup && priv->plat->serdes_powerup) {
 		ret = priv->plat->serdes_powerup(ndev,
 						 priv->plat->bsp_priv);
 
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -270,5 +270,6 @@ struct plat_stmmacenet_data {
 	int msi_tx_base_vec;
 	bool use_phy_wol;
 	bool sph_disable;
+	bool serdes_up_after_phy_linkup;
 };
 #endif