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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Fugang Duan <fugang.duan@nxp.com>,
        Joakim Zhang <qiangqing.zhang@nxp.com>,
        "David S . Miller" <davem@davemloft.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH 4.4 37/57] net: fec_ptp: add clock rate zero check
Date:   Mon, 28 Jun 2021 10:42:36 -0400
Message-Id: <20210628144256.34524-38-sashal@kernel.org>
In-Reply-To: <20210628144256.34524-1-sashal@kernel.org>
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From: Fugang Duan <fugang.duan@nxp.com>

commit cb3cefe3f3f8af27c6076ef7d1f00350f502055d upstream.

Add clock rate zero check to fix coverity issue of "divide by 0".

Fixes: commit 85bd1798b24a ("net: fec: fix spin_lock dead lock")
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/freescale/fec_ptp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index 123181612595..031d4b3a544c 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -586,6 +586,10 @@ void fec_ptp_init(struct platform_device *pdev)
 	fep->ptp_caps.enable = fec_ptp_enable;
 
 	fep->cycle_speed = clk_get_rate(fep->clk_ptp);
+	if (!fep->cycle_speed) {
+		fep->cycle_speed = NSEC_PER_SEC;
+		dev_err(&fep->pdev->dev, "clk_ptp clock rate is zero\n");
+	}
 	fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
 
 	spin_lock_init(&fep->tmreg_lock);
-- 
2.30.2