index 6143f52..84447d9 100644
@@ -51,7 +51,6 @@ MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
 
 static unsigned long wdt_open;
 static unsigned expect_close;
-static spinlock_t io_lock;
 static unsigned char revision;
 
 /* Dog Food address - We use the game port address */

@@ -121,20 +120,27 @@ static inline void superio_select(int ldn)
 	outb(ldn, VAL);
 }
 
-static inline void superio_enter(void)
+static inline int
+superio_enter(void)
 {
-	spin_lock(&io_lock);
+	/*
+	 * Try to reserve REG and REG + 1 for exclusive access.
+	 */
+	if (!request_muxed_region(REG, 2, NAME))
+		return -EBUSY;
+
 	outb(0x87, REG);
 	outb(0x01, REG);
 	outb(0x55, REG);
 	outb(0x55, REG);
+	return 0;
 }
 
 static inline void superio_exit(void)
 {
 	outb(0x02, REG);
 	outb(0x02, VAL);
-	spin_unlock(&io_lock);
+	release_region(REG, 2);
 }
 
 static inline void it8712f_wdt_ping(void)

@@ -173,10 +179,13 @@ static int it8712f_wdt_get_status(void)
 		return 0;
 }
 
-static void it8712f_wdt_enable(void)
+static int it8712f_wdt_enable(void)
 {
+	int ret = superio_enter();
+	if (ret)
+		return ret;
+
 	printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
-	superio_enter();
 	superio_select(LDN_GPIO);
 
 	superio_outb(wdt_control_reg, WDT_CONTROL);

@@ -186,13 +195,18 @@ static void it8712f_wdt_enable(void)
 	superio_exit();
 
 	it8712f_wdt_ping();
+
+	return 0;
 }
 
-static void it8712f_wdt_disable(void)
+static int it8712f_wdt_disable(void)
 {
-	printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
+	int ret = superio_enter();
+
+	if (ret)
+		return ret;
 
-	superio_enter();
+	printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
 	superio_select(LDN_GPIO);
 
 	superio_outb(0, WDT_CONFIG);

@@ -202,6 +216,7 @@ static void it8712f_wdt_disable(void)
 	superio_outb(0, WDT_TIMEOUT);
 
 	superio_exit();
+	return 0;
 }
 
 static int it8712f_wdt_notify(struct notifier_block *this,

@@ -252,6 +267,7 @@ static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
 						WDIOF_MAGICCLOSE,
 	};
 	int value;
+	int ret;
 
 	switch (cmd) {
 	case WDIOC_GETSUPPORT:

@@ -259,7 +275,9 @@ static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
 			return -EFAULT;
 		return 0;
 	case WDIOC_GETSTATUS:
-		superio_enter();
+		ret = superio_enter();
+		if (ret)
+			return ret;
 		superio_select(LDN_GPIO);
 
 		value = it8712f_wdt_get_status();

@@ -280,7 +298,9 @@ static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
 		if (value > (max_units * 60))
 			return -EINVAL;
 		margin = value;
-		superio_enter();
+		ret = superio_enter();
+		if (ret)
+			return -EBUSY;
 		superio_select(LDN_GPIO);
 
 		it8712f_wdt_update_margin();

@@ -299,10 +319,14 @@ static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
 
 static int it8712f_wdt_open(struct inode *inode, struct file *file)
 {
+	int ret;
 	/* only allow one at a time */
 	if (test_and_set_bit(0, &wdt_open))
 		return -EBUSY;
-	it8712f_wdt_enable();
+
+	ret = it8712f_wdt_enable();
+	if (ret)
+		return ret;
 	return nonseekable_open(inode, file);
 }
 

@@ -313,7 +337,8 @@ static int it8712f_wdt_release(struct inode *inode, struct file *file)
 			": watchdog device closed unexpectedly, will not"
 			" disable the watchdog timer\n");
 	} else if (!nowayout) {
-		it8712f_wdt_disable();
+		if (it8712f_wdt_disable())
+			printk(KERN_WARNING NAME "Watchdog disable failed\n");
 	}
 	expect_close = 0;
 	clear_bit(0, &wdt_open);

@@ -340,8 +365,10 @@ static int __init it8712f_wdt_find(unsigned short *address)
 {
 	int err = -ENODEV;
 	int chip_type;
+	int ret = superio_enter();
+	if (ret)
+		return ret;
 
-	superio_enter();
 	chip_type = superio_inw(DEVID);
 	if (chip_type != IT8712F_DEVID)
 		goto exit;

@@ -382,8 +409,6 @@ static int __init it8712f_wdt_init(void)
 {
 	int err = 0;
 
-	spin_lock_init(&io_lock);
-
 	if (it8712f_wdt_find(&address))
 		return -ENODEV;
 

@@ -392,7 +417,8 @@ static int __init it8712f_wdt_init(void)
 		return -EBUSY;
 	}
 
-	it8712f_wdt_disable();
+	if (it8712f_wdt_disable())
+		return -EBUSY;
 
 	err = register_reboot_notifier(&it8712f_wdt_notifier);
 	if (err) {

339 lines not on this page · raw message

index 316b648..fa3ff02 100644
@@ -108,13 +108,20 @@ superio_select(int ldn)
 	outb(ldn, VAL);
 }
 
-static inline 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

@@ -122,6 +129,7 @@ superio_exit(void)
 {
 	outb(0x02, REG);
 	outb(0x02, VAL);
+	release_region(REG, 2);
 }
 
 /* Logical device 4 registers */

@@ -1546,7 +1554,9 @@ static int __init it87_find(unsigned short *address,
 	u16 chip_type;
 	const char *board_vendor, *board_name;
 
-	superio_enter();
+	if (superio_enter())
+		return -EBUSY;
+
 	chip_type = force_id ? force_id : superio_inw(DEVID);
 
 	switch (chip_type) {