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Commit 8bcf6135 authored by Jim Cromie's avatar Jim Cromie Committed by Linus Torvalds
Browse files

[PATCH] chardev: GPIO for SCx200 & PC-8736x: replace spinlocks w 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: default avatarJim Cromie <jim.cromie@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6cad56fd

arch/i386/kernel/scx200.c

+4 −4
Original line number Diff line number Diff line
@@ -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_driver = { 
	.probe = scx200_probe,

};



static DEFINE_SPINLOCK(scx200_gpio_config_lock);

static DEFINE_MUTEX(scx200_gpio_config_lock);



static void __devinit scx200_init_shadow(void)

{
@@ -95,9 +96,8 @@ static int __devinit scx200_probe(struct pci_dev *pdev, const struct pci_device_ 
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, u32 mask, u32 bits) 
	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;

}

drivers/char/pc8736x_gpio.c

+4 −4
Original line number Diff line number Diff line
@@ -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; /* default to dynamic major */ 
module_param(major, int, 0);

MODULE_PARM_DESC(major, "Major device number");



static DEFINE_SPINLOCK(pc8736x_gpio_config_lock);

static 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_fn(unsigned index, u32 mask, u32 bits, 
					    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_fn(unsigned index, u32 mask, u32 bits, 
	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;

}