linux-kernel - [RESEND PATCH net 1/1] net: stmmac: check fwnode for phy device before scanning for phy

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Message-Id: <20230406024541.3556305-1-michael.wei.hong.sit@intel.com>
Date:   Thu,  6 Apr 2023 10:45:41 +0800
From:   Michael Sit Wei Hong <michael.wei.hong.sit@...el.com>
To:     Giuseppe Cavallaro <peppe.cavallaro@...com>,
        Alexandre Torgue <alexandre.torgue@...s.st.com>,
        Jose Abreu <joabreu@...opsys.com>,
        "David S . Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Ong Boon Leong <boon.leong.ong@...el.com>,
        netdev@...r.kernel.org, linux-stm32@...md-mailman.stormreply.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux@...linux.org.uk, hkallweit1@...il.com, andrew@...n.ch,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
        Shahab Vahedi <Shahab.Vahedi@...opsys.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>
Cc:     Looi Hong Aun <hong.aun.looi@...el.com>,
        Voon Weifeng <weifeng.voon@...el.com>,
        Lai Peter Jun Ann <peter.jun.ann.lai@...el.com>,
        Zulkifli Muhammad Husaini <muhammad.husaini.zulkifli@...el.com>,
        Tan Tee Min <tee.min.tan@...el.com>,
        hock.leong.kweh@...el.com
Subject: [RESEND PATCH net 1/1] net: stmmac: check fwnode for phy device before scanning for phy

Some DT devices already have phy device configured in the DT/ACPI.
Current implementation scans for a phy unconditionally even though
there is a phy listed in the DT/ACPI and already attached.

We should check the fwnode if there is any phy device listed in
fwnode and decide whether to scan for a phy to attach to.

Fixes: fe2cfbc96803 ("net: stmmac: check if MAC needs to attach to a PHY")
Reported-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Link: https://lore.kernel.org/lkml/20230403212434.296975-1-martin.blumenstingl@googlemail.com/
Tested-by: Guenter Roeck <linux@...ck-us.net>
Tested-by: Shahab Vahedi <shahab@...opsys.com>
Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Suggested-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@...el.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index d41a5f92aee7..7ca9be7bec06 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1134,22 +1134,26 @@ static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
 static int stmmac_init_phy(struct net_device *dev)
 {
 	struct stmmac_priv *priv = netdev_priv(dev);
+	struct fwnode_handle *phy_fwnode;
 	struct fwnode_handle *fwnode;
-	bool phy_needed;
 	int ret;
 
+	if (!phylink_expects_phy(priv->phylink))
+		return 0;
+
 	fwnode = of_fwnode_handle(priv->plat->phylink_node);
 	if (!fwnode)
 		fwnode = dev_fwnode(priv->device);
 
 	if (fwnode)
-		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, 0);
+		phy_fwnode = fwnode_get_phy_node(fwnode);
+	else
+		phy_fwnode = NULL;
 
-	phy_needed = phylink_expects_phy(priv->phylink);
 	/* Some DT bindings do not set-up the PHY handle. Let's try to
 	 * manually parse it
 	 */
-	if (!fwnode || phy_needed || ret) {
+	if (!phy_fwnode || IS_ERR(phy_fwnode)) {
 		int addr = priv->plat->phy_addr;
 		struct phy_device *phydev;
 
@@ -1165,6 +1169,9 @@ static int stmmac_init_phy(struct net_device *dev)
 		}
 
 		ret = phylink_connect_phy(priv->phylink, phydev);
+	} else {
+		fwnode_handle_put(phy_fwnode);
+		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, 0);
 	}
 
 	if (!priv->plat->pmt) {
-- 
2.34.1