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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Liang He <windhl@126.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 38/71] net: ftgmac100: Hold reference returned by of_get_child_by_name()
Date:   Tue, 19 Jul 2022 13:54:01 +0200
Message-Id: <20220719114555.971850774@linuxfoundation.org>
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From: Liang He <windhl@126.com>

[ Upstream commit 49b9f431ff0d845a36be0b3ede35ec324f2e5fee ]

In ftgmac100_probe(), we should hold the refernece returned by
of_get_child_by_name() and use it to call of_node_put() for
reference balance.

Fixes: 39bfab8844a0 ("net: ftgmac100: Add support for DT phy-handle property")
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/faraday/ftgmac100.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index d7478d332820..98e94d914597 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -1734,6 +1734,19 @@ static void ftgmac100_setup_clk(struct ftgmac100 *priv)
 			FTGMAC_100MHZ);
 }
 
+static bool ftgmac100_has_child_node(struct device_node *np, const char *name)
+{
+	struct device_node *child_np = of_get_child_by_name(np, name);
+	bool ret = false;
+
+	if (child_np) {
+		ret = true;
+		of_node_put(child_np);
+	}
+
+	return ret;
+}
+
 static int ftgmac100_probe(struct platform_device *pdev)
 {
 	struct resource *res;
@@ -1850,7 +1863,7 @@ static int ftgmac100_probe(struct platform_device *pdev)
 
 		/* Display what we found */
 		phy_attached_info(phy);
-	} else if (np && !of_get_child_by_name(np, "mdio")) {
+	} else if (np && !ftgmac100_has_child_node(np, "mdio")) {
 		/* Support legacy ASPEED devicetree descriptions that decribe a
 		 * MAC with an embedded MDIO controller but have no "mdio"
 		 * child node. Automatically scan the MDIO bus for available
-- 
2.35.1