[U-Boot] [PATCH v5 01/20] sandbox: Add architecture header files

Simon Glass sjg at chromium.org
Mon Oct 10 00:04:42 CEST 2011


Hi Wolfgang,

On Sun, Oct 9, 2011 at 12:28 PM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
> In message <1318031631-13643-2-git-send-email-sjg at chromium.org> you wrote:
>> This adds required header files for the sandbox architecture, and a basic
>> description of what sandbox is (README.sandbox).
>>
>> This commit generates a list of 44 checkpatch warnings:
>
> This should go to the comment section.   I don't want to see this as
> part of the commit message.

Neither do I, but I guessed another patch version was coming. I will move it.

>
>> 0 errors, 44 warnings for 0001-sandbox-Add-architecture-header-files.patch:
>> warning: arch/sandbox/include/asm/bitops.h,30: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,32: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,34: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,36: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,44: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,54: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,66: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,76: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,88: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>> warning: arch/sandbox/include/asm/bitops.h,90: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
>>
>> (These are the bitops and seem to have volatile in all the other archs also.)
>
> Existence of bad code examples is no excuse for submitting new bad
> code.

OK. I will drop volatile from the patch. Are you OK with the other
checkpatch problems?

Regards,
Simon

>
> ...
>> +/*
>> + * Function prototypes to keep gcc -Wall happy.
>> + */
>> +extern void set_bit(int nr, volatile void *addr);
>> +
>> +extern void clear_bit(int nr, volatile void *addr);
>> +
>> +extern void change_bit(int nr, volatile void *addr);
>
> I see no reason to accept these voplatiles here.
>
>> +static inline void __change_bit(int nr, volatile void *addr)
>> +{
>> +     unsigned long mask = BIT_MASK(nr);
>> +     unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
>> +
>> +     *p ^= mask;
>
> Please note that you actually even drop the volatile property in your
> implementation.
>
>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> "There is no statute of limitations on stupidity."
> - Randomly produced by a computer program called Markov3.
>


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