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Subject[PATCH] mach-ixp4xx: made gpio functions atomic
Date
gpio_line_set and gpio_line config on ixp4xx were not atomic
This patch fixes this by surrounding them with local_irq_save and
local_irq_restore calls, similar to the way Lennert Buytenhek
implemented this for iop. (see arch/arm/plat-iop/gpio.c)

Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>
---

Note: an alternative solution would be to use the set_bit and
clear_bit atomic functions, but I felt it better to do things
the same way as Lennert did. Also it could be that this is a few
bytes smaller. Didn't check that.

PS: please Cc me as I am not on the list

--- git/arch/arm/mach-ixp4xx/include/mach/platform.h.orig 2011-08-09 19:16:52.645482269 +0200
+++ git/arch/arm/mach-ixp4xx/include/mach/platform.h 2011-08-09 19:17:39.915482235 +0200
@@ -14,6 +14,8 @@
#ifndef __ASSEMBLY__

#include <asm/types.h>
+#include <asm/system.h>
+#include <linux/kernel.h>

#ifndef __ARMEB__
#define REG_OFFSET 0
@@ -150,10 +152,14 @@

static inline void gpio_line_config(u8 line, u32 direction)
{
+ unsigned long flags;
+
+ local_irq_save(flags);
if (direction == IXP4XX_GPIO_IN)
*IXP4XX_GPIO_GPOER |= (1 << line);
else
*IXP4XX_GPIO_GPOER &= ~(1 << line);
+ local_irq_restore(flags);
}

static inline void gpio_line_get(u8 line, int *value)
@@ -163,10 +169,14 @@

static inline void gpio_line_set(u8 line, int value)
{
+ unsigned long flags;
+
+ local_irq_save(flags);
if (value == IXP4XX_GPIO_HIGH)
*IXP4XX_GPIO_GPOUTR |= (1 << line);
else if (value == IXP4XX_GPIO_LOW)
*IXP4XX_GPIO_GPOUTR &= ~(1 << line);
+ local_irq_restore(flags);
}

#endif // __ASSEMBLY__

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