Re: [PATCH] drivers:iio:dac make expression evaluation 64-bit
From: Andy Shevchenko
Date: Wed Dec 22 2021 - 13:51:30 EST
On Wed, Dec 22, 2021 at 5:59 PM Muhammad Usama Anjum
<usama.anjum@xxxxxxxxxxxxx> wrote:
>
> Two 32-bit values are being evaluated using 32-bit arithmetic and then
> passed to s64 type. It is wrong. Expression should be evaluated using
> 64-bit arithmetic and then passed.
...
> dac->ch_data[ch].scale_dec = DIV_ROUND_CLOSEST((s64)rem * 1000000,
> 65536);
Shouldn't the above be fixed as well? Has anybody tried to compile on
32-bit arch this?
> - dac->ch_data[ch].offset_int = div_s64_rem(v_min * 65536, span, &rem);
> + dac->ch_data[ch].offset_int = div_s64_rem(v_min * 65536L, span, &rem);
> tmp = (s64)rem * 1000000;
> dac->ch_data[ch].offset_dec = div_s64(tmp, span);
> }
--
With Best Regards,
Andy Shevchenko