[PATCH 5.4 82/90] net: fec_ptp: add clock rate zero check

From: Greg Kroah-Hartman
Date: Mon Jun 21 2021 - 12:22:07 EST


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
@@ -597,6 +597,10 @@ 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);