[PATCH 5.12 174/178] net: fec_ptp: add clock rate zero check

[Greg Kroah-Hartman]

From: Fugang Duan <fugang.duan@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/freescale/fec_ptp.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -602,6 +602,10 @@ void fec_ptp_init(struct platform_device
 	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);