From: snjw23@gmail.com (Sylwester Nawrocki)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] ARM: EXYNOS: add support GPIO for EXYNOS5250
Date: Sat, 04 Feb 2012 14:46:53 +0100 [thread overview]
Message-ID: <4F2D36CD.3070204@gmail.com> (raw)
In-Reply-To: <20120202182214.GN15343@ponder.secretlab.ca>
On 02/02/2012 07:22 PM, Grant Likely wrote:
>>> /* the end of the EXYNOS4 specific gpios */
>>> #define EXYNOS4_GPIO_END (EXYNOS4_GPZ(EXYNOS4_GPIO_Z_NR) + 1)
>>> -#define S3C_GPIO_END EXYNOS4_GPIO_END
>>>
>>> -/* define the number of gpios we need to the one after the GPZ() range */
>>> -#define ARCH_NR_GPIOS (EXYNOS4_GPZ(EXYNOS4_GPIO_Z_NR) + \
>>> - CONFIG_SAMSUNG_GPIO_EXTRA + 1)
>>> +/* EXYNOS5 serise */
>>> +/* GPIO bank sizes */
>>> +#define EXYNOS5_GPIO_A0_NR (8)
>>
>> nit: It's been always a mystery to me, what are the parentheses around the
>> numbers helpful for ? IMHO even if there is more things like this in
>> the file it might be better to skip extra parentheses here.
>
> It protects against the preprocessor combining a macro with other code in
> unpredictable ways. For example:
>
> #define SIZE 10 + 20
> int i = SIZE * 5;
>
> Without the parenthesis the result of i is 110, when the programmer would
> expect 150.
Right, I guess it's a fundamental requirement most people are aware about.
Nevertheless my point were only single integers.
> For single integers like these, the parenthesis aren't actually necessary, but
> I given that for every other #define it is good practice, I don't object to
> seeing them on single integers also.
I respect that but I have a different opinion. :-) Those parentheses have
always been bugging me, they decrease readability for virtually no benefit.
They're more an aesthetic issue though so I wouldn't argue more about it.
Just will try to get used, and I'll avoid them where possible. :-)
--
Regards,
Sylwester
next prev parent reply other threads:[~2012-02-04 13:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-31 15:50 [PATCH 0/2] ARM: EXYNOS: support GPIO for EXYNOS5250 Kukjin Kim
2012-01-31 15:50 ` [PATCH 1/2] ARM: EXYNOS: add " Kukjin Kim
2012-01-31 16:34 ` Sylwester Nawrocki
2012-02-02 18:22 ` Grant Likely
2012-02-04 13:46 ` Sylwester Nawrocki [this message]
2012-01-31 22:40 ` Russell King - ARM Linux
2012-01-31 23:56 ` Kyungmin Park
2012-02-09 11:48 ` Kukjin Kim
2012-02-02 18:27 ` Grant Likely
2012-02-09 11:44 ` Kukjin Kim
2012-01-31 15:50 ` [PATCH 2/2] gpio/samsung: add support GPIOlib " Kukjin Kim
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