[U-Boot] [PATCH v4 2/7] gpio: Add Multi-Function-Pin configuration driver for Marvell SoCs

[Albert ARIBAUD]

Hi Chris,

Le 09/12/2010 07:11, Chris Moore a écrit :
> Hi,
>
> Le 07/12/2010 18:39, Albert ARIBAUD a écrit :
>> Le 07/12/2010 18:10, Prafulla Wadaskar a écrit :
>>
>>>>> + val&= ~MFP_AF_MASK;
>>>> Do we need to do this& here? For val is only 0 here...
>>> This can be removed.
>> OTOH, with the&, this line makes no assumption about val, and thus will
>> work regardless of it. If the& is removed, and if later val is set to
>> non-zero before reaching this instruction, it will cause a bug.
>>
>> IOW, the& makes the statement more resilient.
>>
>
> If val really is zero then the result will always be zero :(
> Simply removing the & would give a different result.
> It would be better to remove the whole bloody line ;-)
>
> I haven't followed this thread but I suspect the original code was wrong.

Good point as to the removal if the removal must be done :)

I still think that the original is functionally more correct *if we are 
not sure that val will always be zero.

I'll have a second look tonight.

> Cheers,
> Chris

Amicalement,
-- 
Albert.