From: Arnd Bergmann <arnd@arndb.de>
To: Grant Likely <grant.likely@secretlab.ca>
Subject: Re: [PATCH] gpio/exynos: Fix compiler warnings when non-exynos machines are selected
Date: Tue, 15 May 2012 12:08:26 +0000
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Cc: Linus Walleij <linus.walleij@linaro.org>,
        Sachin Kamat <sachin.kamat@linaro.org>, linux-kernel@vger.kernel.org,
        linus.walleij@stericsson.com, patches@linaro.org
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On Saturday 12 May 2012, Grant Likely wrote:
> On Wed, 2 May 2012 01:26:12 +0200, Linus Walleij <linus.walleij@linaro.org> wrote:
> > On Mon, Apr 30, 2012 at 8:52 AM, Sachin Kamat <sachin.kamat@linaro.org> wrote:
> > 
> > > +#if defined(CONFIG_ARCH_EXYNOS4) || defined(CONFIG_ARCH_EXYNOS5)
> > > +#endif
> > > -static struct samsung_gpio_chip exynos4_gpios_1[] = {
> > > ? #ifdef CONFIG_ARCH_EXYNOS4
> > > +static struct samsung_gpio_chip exynos4_gpios_1[] = {
> > > -#endif
> > > +#endif
> > > -static struct samsung_gpio_chip exynos4_gpios_2[] = {
> > > ? #ifdef CONFIG_ARCH_EXYNOS4
> > > +static struct samsung_gpio_chip exynos4_gpios_2[] = {
> > > -#endif
> > > +#endif
> > > -static struct samsung_gpio_chip exynos4_gpios_3[] = {
> > > ? #ifdef CONFIG_ARCH_EXYNOS4
> > > +static struct samsung_gpio_chip exynos4_gpios_3[] = {
> > > -#endif
> > > +#endif
> > > ? #ifdef CONFIG_ARCH_EXYNOS5
> > > +#if defined(CONFIG_CPU_EXYNOS4210) || defined(CONFIG_SOC_EXYNOS5250)
> > > +#endif
> > > +#if defined(CONFIG_CPU_EXYNOS4210) || defined(CONFIG_SOC_EXYNOS5250)
> > > +#endif
> > 
> > We really want to get rid of this kind of stuff from all drivers, #ifdefs are
> > declared ugly already in Documentation/CodingStyle.
> > 
> > Any chance you could solve this problem by reworking the driver to
> > pass some flag in platform data tell which exynos it's for
> > and jist adapt at runtime instead of the compile-time quirkiness?
> > 
> > Besides looking better, it helps us to get to a single zImage for the
> > exynoses too..
> 
> I don't see any single-zImage issues here.  There are no #else clauses
> in the #ifdef blocks so all it does it compile out unused code when
> exynos4 & 5 is not enabled. I'm going to apply it.


I needed another fixup on top of this to build exynos4_defconfig without
warnings.

8<---
gpio/samsung: define gpio_base4 variable only for exynos5

Avoids this warning:
drivers/gpio/gpio-samsung.c: In function 'samsung_gpiolib_init':
drivers/gpio/gpio-samsung.c:2979:1: warning: label 'err_ioremap4' defined but not used [-Wunused-label]
drivers/gpio/gpio-samsung.c:2725:47: warning: unused variable 'gpio_base4' [-Wunused-variable]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/gpio/gpio-samsung.c b/drivers/gpio/gpio-samsung.c
index e991d91..c80356d 100644
--- a/drivers/gpio/gpio-samsung.c
+++ b/drivers/gpio/gpio-samsung.c
@@ -2722,7 +2722,10 @@ static __init int samsung_gpiolib_init(void)
 	struct samsung_gpio_chip *chip;
 	int i, nr_chips;
 #if defined(CONFIG_CPU_EXYNOS4210) || defined(CONFIG_SOC_EXYNOS5250)
-	void __iomem *gpio_base1, *gpio_base2, *gpio_base3, *gpio_base4;
+	void __iomem *gpio_base1, *gpio_base2, *gpio_base3;
+#endif
+#if defined(CONFIG_SOC_EXYNOS5250)
+	void __iomem *gpio_base4;
 #endif
 	int group = 0;
 
@@ -2975,9 +2978,11 @@ static __init int samsung_gpiolib_init(void)
 
 	return 0;
 
-#if defined(CONFIG_CPU_EXYNOS4210) || defined(CONFIG_SOC_EXYNOS5250)
+#if defined(CONFIG_SOC_EXYNOS5250)
 err_ioremap4:
 	iounmap(gpio_base3);
+#endif
+#if defined(CONFIG_CPU_EXYNOS4210) || defined(CONFIG_SOC_EXYNOS5250)
 err_ioremap3:
 	iounmap(gpio_base2);
 err_ioremap2:
--
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