netdev - [PATCH] net: macb: fix for fixed-link mode

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Message-ID: <1578885992-42113-1-git-send-email-mparab@cadence.com>
Date:   Mon, 13 Jan 2020 03:26:32 +0000
From:   Milind Parab <mparab@...ence.com>
To:     <nicolas.ferre@...rochip.com>, <jakub.kicinski@...ronome.com>,
        <andrew@...n.ch>, <antoine.tenart@...tlin.com>,
        <rmk+kernel@...linux.org.uk>
CC:     <Claudiu.Beznea@...rochip.com>, <f.fainelli@...il.com>,
        <davem@...emloft.net>, <netdev@...r.kernel.org>,
        <hkallweit1@...il.com>, <linux-kernel@...r.kernel.org>,
        <dkangude@...ence.com>, <a.fatoum@...gutronix.de>,
        <brad.mouring@...com>, <pthombar@...ence.com>,
        Milind Parab <mparab@...ence.com>
Subject: [PATCH] net: macb: fix for fixed-link mode

This patch fix the issue with fixed link. With fixed-link
device opening fails due to macb_phylink_connect not
handling fixed-link mode, in which case no MAC-PHY connection
is needed and phylink_connect return success (0), however
in current driver attempt is made to search and connect to
PHY even for fixed-link.

Fixes: 7897b071ac3b ("net: macb: convert to phylink")
Signed-off-by: Milind Parab <mparab@...ence.com>
---
Changes in v2:
1. Code refactoring to remove extra if condition

Changes in v3:
1. Reverse christmas tree ordering of local variables
---
 drivers/net/ethernet/cadence/macb_main.c | 30 ++++++++++++++----------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 1c547ee0d444..7a2fe63d1136 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -650,21 +650,24 @@ static const struct phylink_mac_ops macb_phylink_ops = {
 	.mac_link_up = macb_mac_link_up,
 };
 
+static bool macb_phy_handle_exists(struct device_node *dn)
+{
+	dn = of_parse_phandle(dn, "phy-handle", 0);
+	of_node_put(dn);
+	return dn != NULL;
+}
+
 static int macb_phylink_connect(struct macb *bp)
 {
+	struct device_node *dn = bp->pdev->dev.of_node;
 	struct net_device *dev = bp->dev;
 	struct phy_device *phydev;
 	int ret;
 
-	if (bp->pdev->dev.of_node &&
-	    of_parse_phandle(bp->pdev->dev.of_node, "phy-handle", 0)) {
-		ret = phylink_of_phy_connect(bp->phylink, bp->pdev->dev.of_node,
-					     0);
-		if (ret) {
-			netdev_err(dev, "Could not attach PHY (%d)\n", ret);
-			return ret;
-		}
-	} else {
+	if (dn)
+		ret = phylink_of_phy_connect(bp->phylink, dn, 0);
+
+	if (!dn || (ret && !macb_phy_handle_exists(dn))) {
 		phydev = phy_find_first(bp->mii_bus);
 		if (!phydev) {
 			netdev_err(dev, "no PHY found\n");
@@ -673,10 +676,11 @@ static int macb_phylink_connect(struct macb *bp)
 
 		/* attach the mac to the phy */
 		ret = phylink_connect_phy(bp->phylink, phydev);
-		if (ret) {
-			netdev_err(dev, "Could not attach to PHY (%d)\n", ret);
-			return ret;
-		}
+	}
+
+	if (ret) {
+		netdev_err(dev, "Could not attach PHY (%d)\n", ret);
+		return ret;
 	}
 
 	phylink_start(bp->phylink);
-- 
2.17.1