From ca26475bf02ed8562b9b46f91d3e8b52ec312541 Mon Sep 17 00:00:00 2001 From: Robert Jarzmik Date: Tue, 2 Aug 2016 00:01:32 +0200 Subject: ARM: pxa: fix GPIO double shifts The commit 9bf448c66d4b ("ARM: pxa: use generic gpio operation instead of gpio register") from Oct 17, 2011, leads to the following static checker warning: arch/arm/mach-pxa/spitz_pm.c:172 spitz_charger_wakeup() warn: double left shift '!gpio_get_value(SPITZ_GPIO_KEY_INT) << (1 << ((SPITZ_GPIO_KEY_INT) & 31))' As Dan reported, the value is shifted three times : - once by gpio_get_value(), which returns either 0 or BIT(gpio) - once by the shift operation '<<' - a last time by GPIO_bit(gpio) which is BIT(gpio) Therefore the calculation lead to a chained or operator of : - (1 << gpio) << (1 << gpio) = (2^gpio)^gpio = 2 ^ (gpio * gpio) It is be sheer luck the former statement works, only because each gpio used is strictly smaller than 6, and therefore 2^(gpio^2) never overflows a 32 bits value, and because it is used as a boolean value to check a gpio activation. As the xxx_charger_wakeup() functions are used as a true/false detection mechanism, take that opportunity to change their prototypes from integer return value to boolean one. Fixes: 9bf448c66d4b ("ARM: pxa: use generic gpio operation instead of gpio register") Reported-by: Dan Carpenter Cc: Joe Perches Signed-off-by: Robert Jarzmik --- arch/arm/mach-pxa/sharpsl_pm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mach-pxa/sharpsl_pm.h') diff --git a/arch/arm/mach-pxa/sharpsl_pm.h b/arch/arm/mach-pxa/sharpsl_pm.h index 905be6755f04..fa75b6df8134 100644 --- a/arch/arm/mach-pxa/sharpsl_pm.h +++ b/arch/arm/mach-pxa/sharpsl_pm.h @@ -34,7 +34,7 @@ struct sharpsl_charger_machinfo { #define SHARPSL_STATUS_LOCK 5 #define SHARPSL_STATUS_CHRGFULL 6 #define SHARPSL_STATUS_FATAL 7 - unsigned long (*charger_wakeup)(void); + bool (*charger_wakeup)(void); int (*should_wakeup)(unsigned int resume_on_alarm); void (*backlight_limit)(int); int (*backlight_get_status) (void); -- cgit v1.2.1