Merge branch 'net-stmmac-fix-serdes-power-methods'

Russell King says:

====================
net: stmmac: fix serdes power methods

The stmmac serdes powerup/powerdown methods are not guaranteed to be
called in a balancing fashion, but these are used to call the generic
PHY subsystem's phy_power_up() and phy_power_down() methods which do
require balanced calls.

This series addresses this by making the stmmac serdes methods balanced.
====================

Link: https://patch.msgid.link/aYHHWm5UkD1JVa7D@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 41 insertions, 25 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 012b0a477255..5bd97aaaba86 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -303,6 +303,7 @@ struct stmmac_priv {
 	bool eee_enabled;
 	bool eee_active;
 	bool eee_sw_timer_en;
+	bool legacy_serdes_is_powered;
 	unsigned int mode;
 	unsigned int chain_mode;
 	int extend_desc;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 9500b332a152..d561b0a0f5ac 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -882,6 +882,30 @@ static void stmmac_release_ptp(struct stmmac_priv *priv)
 	clk_disable_unprepare(priv->plat->clk_ptp_ref);
 }
 
+static void stmmac_legacy_serdes_power_down(struct stmmac_priv *priv)
+{
+	if (priv->plat->serdes_powerdown && priv->legacy_serdes_is_powered)
+		priv->plat->serdes_powerdown(priv->dev, priv->plat->bsp_priv);
+
+	priv->legacy_serdes_is_powered = false;
+}
+
+static int stmmac_legacy_serdes_power_up(struct stmmac_priv *priv)
+{
+	int ret;
+
+	if (!priv->plat->serdes_powerup)
+		return 0;
+
+	ret = priv->plat->serdes_powerup(priv->dev, priv->plat->bsp_priv);
+	if (ret < 0)
+		netdev_err(priv->dev, "SerDes powerup failed\n");
+	else
+		priv->legacy_serdes_is_powered = true;
+
+	return ret;
+}
+
 /**
  *  stmmac_mac_flow_ctrl - Configure flow control in all queues
  *  @priv: driver private structure
@@ -981,9 +1005,8 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 	u32 old_ctrl, ctrl;
 	int ret;
 
-	if ((priv->plat->flags & STMMAC_FLAG_SERDES_UP_AFTER_PHY_LINKUP) &&
-	    priv->plat->serdes_powerup)
-		priv->plat->serdes_powerup(priv->dev, priv->plat->bsp_priv);
+	if (priv->plat->flags & STMMAC_FLAG_SERDES_UP_AFTER_PHY_LINKUP)
+		stmmac_legacy_serdes_power_up(priv);
 
 	old_ctrl = readl(priv->ioaddr + MAC_CTRL_REG);
 	ctrl = old_ctrl & ~priv->hw->link.speed_mask;
@@ -4111,16 +4134,6 @@ static int __stmmac_open(struct net_device *dev,
 
 	stmmac_reset_queues_param(priv);
 
-	if (!(priv->plat->flags & STMMAC_FLAG_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",
-				   __func__);
-			goto init_error;
-		}
-	}
-
 	ret = stmmac_hw_setup(dev);
 	if (ret < 0) {
 		netdev_err(priv->dev, "%s: Hw setup failed\n", __func__);
@@ -4176,9 +4189,15 @@ static int stmmac_open(struct net_device *dev)
 	if (ret)
 		goto err_runtime_pm;
 
+	if (!(priv->plat->flags & STMMAC_FLAG_SERDES_UP_AFTER_PHY_LINKUP)) {
+		ret = stmmac_legacy_serdes_power_up(priv);
+		if (ret < 0)
+			goto err_disconnect_phy;
+	}
+
 	ret = __stmmac_open(dev, dma_conf);
 	if (ret)
-		goto err_disconnect_phy;
+		goto err_serdes;
 
 	kfree(dma_conf);
 
@@ -4187,6 +4206,8 @@ static int stmmac_open(struct net_device *dev)
 
 	return ret;
 
+err_serdes:
+	stmmac_legacy_serdes_power_down(priv);
 err_disconnect_phy:
 	phylink_disconnect_phy(priv->phylink);
 err_runtime_pm:
@@ -4221,10 +4242,6 @@ static void __stmmac_release(struct net_device *dev)
 	/* Release and free the Rx/Tx resources */
 	free_dma_desc_resources(priv, &priv->dma_conf);
 
-	/* Powerdown Serdes if there is */
-	if (priv->plat->serdes_powerdown)
-		priv->plat->serdes_powerdown(dev, priv->plat->bsp_priv);
-
 	stmmac_release_ptp(priv);
 
 	if (stmmac_fpe_supported(priv))
@@ -4250,6 +4267,7 @@ static int stmmac_release(struct net_device *dev)
 
 	__stmmac_release(dev);
 
+	stmmac_legacy_serdes_power_down(priv);
 	phylink_disconnect_phy(priv->phylink);
 	pm_runtime_put(priv->device);
 
@@ -8130,8 +8148,7 @@ int stmmac_suspend(struct device *dev)
 	/* Stop TX/RX DMA */
 	stmmac_stop_all_dma(priv);
 
-	if (priv->plat->serdes_powerdown)
-		priv->plat->serdes_powerdown(ndev, priv->plat->bsp_priv);
+	stmmac_legacy_serdes_power_down(priv);
 
 	/* Enable Power down mode by programming the PMT regs */
 	if (priv->wolopts) {
@@ -8233,11 +8250,8 @@ int stmmac_resume(struct device *dev)
 			stmmac_mdio_reset(priv->mii);
 	}
 
-	if (!(priv->plat->flags & STMMAC_FLAG_SERDES_UP_AFTER_PHY_LINKUP) &&
-	    priv->plat->serdes_powerup) {
-		ret = priv->plat->serdes_powerup(ndev,
-						 priv->plat->bsp_priv);
-
+	if (!(priv->plat->flags & STMMAC_FLAG_SERDES_UP_AFTER_PHY_LINKUP)) {
+		ret = stmmac_legacy_serdes_power_up(priv);
 		if (ret < 0)
 			return ret;
 	}
@@ -8259,6 +8273,7 @@ int stmmac_resume(struct device *dev)
 	ret = stmmac_hw_setup(ndev);
 	if (ret < 0) {
 		netdev_err(priv->dev, "%s: Hw setup failed\n", __func__);
+		stmmac_legacy_serdes_power_down(priv);
 		mutex_unlock(&priv->lock);
 		rtnl_unlock();
 		return ret;