Re: [PATCH v4] iio: adc: ad4030: fix invalid oversampling_ratio validation

[Andy Shevchenko]

On Tue, Sep 01, 2026 at 11:42:43AM +0100, Salah Triki wrote:
> In ad4030_set_avg_frame_len(), the logarithm is calculated before input
> validation. Passing zero or negative values leads to an undefined result
> from ilog2().
> 
> Validate that the input is strictly positive prior to computing its
> logarithm to ensure only valid values are processed.

...

> -	if (avg_val < 0 || avg_val > ad4030_average_modes[last_avg_idx])
> +	if (avg_val <= 0 || avg_val > ad4030_average_modes[last_avg_idx])
>  		return -EINVAL;

I still find '<= 0' confusing. Why not check against 1?
And I would rather see an additional comment.

What about

	/* Reject unsupported modes */
	if (avg_val > ad4030_average_modes[last_avg_idx])
		return -EINVAL;

	/* Avoid invalid values for logarithm since it's undefined */
	if (avg_val < 1)
// In this case, when condition is split, if (avg_val <= 0) is also possible
		return -EINVAL;

> +	avg_log2 = ilog2(avg_val);

-- 
With Best Regards,
Andy Shevchenko