Re: [PATCH] net: ethernet: ti: Prevent divide-by-zero in cpts_calc_mult_shift()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Aug 28, 2025 at 05:22:23PM +0800, Miaoqian Lin wrote:
> cpts_calc_mult_shift() has a potential divide-by-zero in this line:
> 
>         do_div(maxsec, freq);
> 
> due to the fact that clk_get_rate() can return zero in certain error
> conditions.
> Add an explicit check to fix this.
> 
> Fixes: 88f0f0b0bebf ("net: ethernet: ti: cpts: calc mult and shift from refclk freq")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> This follows the same pattern as the fix in commit 7ca59947b5fc
> ("pwm: mediatek: Prevent divide-by-zero in pwm_mediatek_config()").
> ---
>  drivers/net/ethernet/ti/cpts.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
> index 2ba4c8795d60..e4e3409e7648 100644
> --- a/drivers/net/ethernet/ti/cpts.c
> +++ b/drivers/net/ethernet/ti/cpts.c
> @@ -607,6 +607,8 @@ static void cpts_calc_mult_shift(struct cpts *cpts)
>  	u32 freq;
>  
>  	freq = clk_get_rate(cpts->refclk);
> +	if (!freq)
> +		return;
>  
>  	/* Calc the maximum number of seconds which we can run before
>  	 * wrapping around.
> -- 
> 2.39.5 (Apple Git-154)
> 


Hi,

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