Re: [PATCH net 1/2] net: fec_ptp: add clock rate zero check
From: "Russell King (Oracle)" <linux@armlinux.org.uk>
Date: 2021-06-16 10:20:56
Also in:
linux-arm-kernel, lkml
On Wed, Jun 16, 2021 at 05:14:25PM +0800, Joakim Zhang wrote:
quoted hunk ↗ jump to hunk
From: Fugang Duan <redacted> 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 <redacted> Signed-off-by: Joakim Zhang <redacted> --- 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 1753807cbf97..7326a0612823 100644 --- a/drivers/net/ethernet/freescale/fec_ptp.c +++ b/drivers/net/ethernet/freescale/fec_ptp.c@@ -604,6 +604,10 @@ void fec_ptp_init(struct platform_device *pdev, int irq_idx) 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");
If this is supposed to be an error message, it doesn't convey that something is really wrong to the user. Maybe something like this would be more meaningful to the user: "PTP clock rate should not be zero, using 1GHz instead. PTP clock may be unreliable.\n" It may be appropriate not to publish PTP support for the interface if we don't have a valid clock rate, which is probably the safer approach and would probably make the problem more noticable to the end user so it gets fixed. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!