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SubjectRe: [PATCH] iio:proximity:sx9324: Fix hardware gain read/write
On Sat, Mar 19, 2022 at 5:58 AM Stephen Boyd <swboyd@chromium.org> wrote:
>
> There are four possible gain values according to sx9324_gain_vals[]: 1,
> 2, 4, and 8. When writing and reading the register the values are off by
> one. The bits should be set according to this equation:
>
> ilog2(<gain>) + 1
>
> so that a gain of 8 is 0x3 in the register field and a gain of 4 is 0x2
> in the register field, etc. Fix up the functions.

...

> + *val = 1 << regval;

I see it's similar in the original code, but this is still problematic
from C standard point of view, i.e. if regval = 31, the C standard
calls it UB (Undefined Behaviour).

--
With Best Regards,
Andy Shevchenko

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