[patch -mm 17/20] chardev: GPIO for SCx200 & PC-8736x: replace spinlocksw mutexes

[Jim Cromie]

17/20. patch.mutexes

Replace spinlocks guarding gpio config ops with mutexes.  This is a
me-too patch, and is justifiable insofar as mutexes have stricter
semantics and better debugging support, so are preferred where they
are applicable.

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>

---

diffstat gpio-scx/patch.mutexes
arch/i386/kernel/scx200.c   |    8 ++++----
drivers/char/pc8736x_gpio.c |    8 ++++----
2 files changed, 8 insertions(+), 8 deletions(-)

diff -ruNp -X dontdiff -X exclude-diffs ax-16/arch/i386/kernel/scx200.c ax-17/arch/i386/kernel/scx200.c
--- ax-16/arch/i386/kernel/scx200.c	2006-06-17 01:36:56.000000000 -0600
+++ ax-17/arch/i386/kernel/scx200.c	2006-06-17 01:51:49.000000000 -0600
@@ -9,6 +9,7 @@
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/mutex.h>
#include <linux/pci.h>

#include <linux/scx200.h>
@@ -45,7 +46,7 @@ static struct pci_driver scx200_pci_driv
	.probe = scx200_probe,
};

-static DEFINE_SPINLOCK(scx200_gpio_config_lock);
+DEFINE_MUTEX(scx200_gpio_config_lock);

static void __devinit scx200_init_shadow(void)
{
@@ -95,9 +96,8 @@ static int __devinit scx200_probe(struct
u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits)
{
	u32 config, new_config;
-	unsigned long flags;

-	spin_lock_irqsave(&scx200_gpio_config_lock, flags);
+	mutex_lock(&scx200_gpio_config_lock);

	outl(index, scx200_gpio_base + 0x20);
	config = inl(scx200_gpio_base + 0x24);
@@ -105,7 +105,7 @@ u32 scx200_gpio_configure(unsigned index
	new_config = (config & mask) | bits;
	outl(new_config, scx200_gpio_base + 0x24);

-	spin_unlock_irqrestore(&scx200_gpio_config_lock, flags);
+	mutex_unlock(&scx200_gpio_config_lock);

	return config;
}
diff -ruNp -X dontdiff -X exclude-diffs ax-16/drivers/char/pc8736x_gpio.c ax-17/drivers/char/pc8736x_gpio.c
--- ax-16/drivers/char/pc8736x_gpio.c	2006-06-17 01:48:50.000000000 -0600
+++ ax-17/drivers/char/pc8736x_gpio.c	2006-06-17 01:51:49.000000000 -0600
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/ioport.h>
+#include <linux/mutex.h>
#include <linux/nsc_gpio.h>
#include <linux/platform_device.h>
#include <asm/uaccess.h>
@@ -31,7 +32,7 @@ static int major = 0;		/* default to dyn
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");

-static DEFINE_SPINLOCK(pc8736x_gpio_config_lock);
+DEFINE_MUTEX(pc8736x_gpio_config_lock);
static unsigned pc8736x_gpio_base;
static u8 pc8736x_gpio_shadow[4];

@@ -119,9 +120,8 @@ static inline u32 pc8736x_gpio_configure
					    u32 func_slct)
{
	u32 config, new_config;
-	unsigned long flags;

-	spin_lock_irqsave(&pc8736x_gpio_config_lock, flags);
+	mutex_lock(&pc8736x_gpio_config_lock);

	device_select(SIO_GPIO_UNIT);
	select_pin(index);
@@ -133,7 +133,7 @@ static inline u32 pc8736x_gpio_configure
	new_config = (config & mask) | bits;
	superio_outb(func_slct, new_config);

-	spin_unlock_irqrestore(&pc8736x_gpio_config_lock, flags);
+	mutex_unlock(&pc8736x_gpio_config_lock);

	return config;
}


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