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Commit 5b0380c9 authored by Nat Gurumoorthy's avatar Nat Gurumoorthy Committed by Jean Delvare
Browse files

hwmon: (it87) Use request_muxed_region 



Serialize access to the hardware by using "request_muxed_region" macro
defined by Alan Cox. Call to this macro will hold off the requestor if
the resource is currently busy. "superio_enter" will return an error
if call to "request_muxed_region" fails. Rest of the code change is to
ripple an error return from superio_enter to the top level.

Signed-off-by: default avatarNat Gurumoorthy <natg@google.com>
Acked-by: default avatarGuenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 357b9dc6

drivers/hwmon/it87.c

+19 −12
Original line number Diff line number Diff line
@@ -77,15 +77,13 @@ static struct platform_device *pdev; 
#define	DEVID	0x20	/* Register: Device ID */

#define	DEVREV	0x22	/* Register: Device Revision */



static inline int

superio_inb(int reg)

static inline int superio_inb(int reg)

{

	outb(reg, REG);

	return inb(VAL);

}



static inline void

superio_outb(int reg, int val)

static inline void superio_outb(int reg, int val)

{

	outb(reg, REG);

	outb(val, VAL);
@@ -101,27 +99,32 @@ static int superio_inw(int reg) 
	return val;

}



static inline void

superio_select(int ldn)

static inline void superio_select(int ldn)

{

	outb(DEV, REG);

	outb(ldn, VAL);

}



static inline void

superio_enter(void)

static inline int superio_enter(void)

{

	/*

	 * Try to reserve REG and REG + 1 for exclusive access.

	 */

	if (!request_muxed_region(REG, 2, DRVNAME))

		return -EBUSY;



	outb(0x87, REG);

	outb(0x01, REG);

	outb(0x55, REG);

	outb(0x55, REG);

	return 0;

}



static inline void

superio_exit(void)

static inline void superio_exit(void)

{

	outb(0x02, REG);

	outb(0x02, VAL);

	release_region(REG, 2);

}



/* Logical device 4 registers */
@@ -1542,11 +1545,15 @@ static const struct attribute_group it87_group_label = { 
static int __init it87_find(unsigned short *address,

	struct it87_sio_data *sio_data)

{

	int err = -ENODEV;

	int err;

	u16 chip_type;

	const char *board_vendor, *board_name;



	superio_enter();

	err = superio_enter();

	if (err)

		return err;



	err = -ENODEV;

	chip_type = force_id ? force_id : superio_inw(DEVID);



	switch (chip_type) {