On 09/03/2016 05:13 PM, Jonathan Cameron wrote:
> On 02/09/16 19:27, Gregor Boirie wrote:
>> 7985e7c100 ("iio: Introduce a new fractional value type") introduced a
>> new IIO_VAL_FRACTIONAL value type meant to represent rational type numbers
>> expressed by a numerator and denominator combination.
>>
>> Formating of IIO_VAL_FRACTIONAL values relies upon do_div() usage. This
>> fails handling negative values properly since parameters are reevaluated
>> as unsigned values.
>> Fix this by using div_s64_rem() instead. Computed integer part will carry
>> properly signed value. Formatted fractional part will always be positive.
>>
>> Fixes: 7985e7c100 ("iio: Introduce a new fractional value type")
>> Signed-off-by: Gregor Boirie <gregor.boirie@xxxxxxxxxx>
>
> Hi Gregor,
>
> While this looks sensible to me, I always gain an almighty headache when
> I hit the various divide functions.
>
> Lars, the fractional code was yours in the first place.
> If you have time can you sanity check this please.
Looks good. While looking into this I noticed that we have a very similar
patch[1] in our tree, seems like somebody forgot to send that upstream.
Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
[1]
https://github.com/analogdevicesinc/linux/commit/1dbcdcfd0c8d3f5513572697685d9f30ba49d851
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
