Re: [PATCH v3] iio: adc: ad4030: fix invalid oversampling_ratio validation

[Salah Triki]

Hi Andy,

Sorry for the confusion - my previous v3 email crossed paths with yours.
Regarding is_power_of_2(avg_val): following feedback from David and 
Jonathan, we agreed to keep only the check for non-positive values
(avg_val <= 0) to avoid the invalid ilog2(0) call. Checking for non-powers
of two was dropped to preserve standard IIO attribute rounding behavior.

I will sent v4 addressing all your formatting and style requirements.

Thanks for your patience and thorough review.

Best regards,
Salah Triki

On Mon, Aug 24, 2026 at 05:54:31PM +0300, Andy Shevchenko wrote:
> On Mon, Aug 24, 2026 at 06:10:26AM +0100, Salah Triki wrote:
> > ad4030_set_avg_frame_len() computes avg_log2 = ilog2(avg_val) before
> > validating avg_val. The existing check (avg_val < 0) allows avg_val == 0
> 
> Try to write the sentences straight to the point using plain English,
> Avoid using C language as substitute of plain English.
> 
> > to pass through, resulting in ilog2(0) being called with undefined/garbage
> > behavior.
> > 
> > Reject non-positive values (avg_val <= 0) before computing log2.
> > 
> > This issue was identified with assistance from Claude AI and manually
> > verified against the code.
> 
> > Changes since v1:
> >    - Added note stating the issue was identified with assistance from
> >    Claude AI and verified manually.
> 
> Assisted-by?
> 
> ...
> 
> >  static int ad4030_set_avg_frame_len(struct iio_dev *dev, int avg_val)
> >  {
> >  	struct ad4030_state *st = iio_priv(dev);
> > -	unsigned int avg_log2 = ilog2(avg_val);
> > +	unsigned int avg_log2;
> 
> Have you read my comments to the previous version?
> 
> >  	unsigned int last_avg_idx = ARRAY_SIZE(ad4030_average_modes) - 1;
> >  	int freq_hz;
> >  	int ret;
> >  
> > -	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;
> 
> Ditto.
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
>