linux-kernel - [PATCH net v2 2/2] sh_eth: avoid PHY being resumed when interface is not up

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Message-Id: <20230315074115.3008-3-wsa+renesas@sang-engineering.com>
Date:   Wed, 15 Mar 2023 08:41:15 +0100
From:   Wolfram Sang <wsa+renesas@...g-engineering.com>
To:     netdev@...r.kernel.org
Cc:     linux-renesas-soc@...r.kernel.org,
        Wolfram Sang <wsa+renesas@...g-engineering.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Michal Kubiak <michal.kubiak@...el.com>,
        Sergey Shtylyov <s.shtylyov@....ru>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Florian Fainelli <f.fainelli@...il.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH net v2 2/2] sh_eth: avoid PHY being resumed when interface is not up

SH_ETH doesn't need mdiobus suspend/resume, that's why it sets
'mac_managed_pm'. However, setting it needs to be moved from init to
probe, so mdiobus PM functions will really never be called (e.g. when
the interface is not up yet during suspend/resume).

Fixes: 6a1dbfefdae4 ("net: sh_eth: Fix PHY state warning splat during system resume")
Suggested-by: Heiner Kallweit <hkallweit1@...il.com>
Signed-off-by: Wolfram Sang <wsa+renesas@...g-engineering.com>
Reviewed-by: Michal Kubiak <michal.kubiak@...el.com>
---
 drivers/net/ethernet/renesas/sh_eth.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index ed17163d7811..d8ec729825be 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -2029,8 +2029,6 @@ static int sh_eth_phy_init(struct net_device *ndev)
 	if (mdp->cd->register_type != SH_ETH_REG_GIGABIT)
 		phy_set_max_speed(phydev, SPEED_100);
 
-	/* Indicate that the MAC is responsible for managing PHY PM */
-	phydev->mac_managed_pm = true;
 	phy_attached_info(phydev);
 
 	return 0;
@@ -3097,6 +3095,8 @@ static int sh_mdio_init(struct sh_eth_private *mdp,
 	struct bb_info *bitbang;
 	struct platform_device *pdev = mdp->pdev;
 	struct device *dev = &mdp->pdev->dev;
+	struct phy_device *phydev;
+	struct device_node *pn;
 
 	/* create bit control struct for PHY */
 	bitbang = devm_kzalloc(dev, sizeof(struct bb_info), GFP_KERNEL);
@@ -3133,6 +3133,14 @@ static int sh_mdio_init(struct sh_eth_private *mdp,
 	if (ret)
 		goto out_free_bus;
 
+	pn = of_parse_phandle(dev->of_node, "phy-handle", 0);
+	phydev = of_phy_find_device(pn);
+	if (phydev) {
+		phydev->mac_managed_pm = true;
+		put_device(&phydev->mdio.dev);
+	}
+	of_node_put(pn);
+
 	return 0;
 
 out_free_bus:
-- 
2.30.2