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authorWim Van Sebroeck <wim@iguana.be>2009-02-23 13:08:36 +0000
committerWim Van Sebroeck <wim@iguana.be>2009-03-25 09:01:50 +0000
commite455b6b4ed66be0c2aa6e41fd9027c1ce585a490 (patch)
treefcc99995d1ccf7a441e3ca09cbfa9c6f4eca0ec7 /drivers
parent0aaae66179f269b7b37d0b526029c5783bed1da3 (diff)
[WATCHDOG] rc32434_wdt: add spin_locking
Add spin_locks to prevent races. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/watchdog/rc32434_wdt.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c
index eee29923a14..bffd4a2b115 100644
--- a/drivers/watchdog/rc32434_wdt.c
+++ b/drivers/watchdog/rc32434_wdt.c
@@ -28,6 +28,7 @@
#include <linux/watchdog.h> /* For the watchdog specific items */
#include <linux/init.h> /* For __init/__exit/... */
#include <linux/platform_device.h> /* For platform_driver framework */
+#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
#include <asm/mach-rc32434/integ.h> /* For the Watchdog registers */
@@ -38,6 +39,7 @@
static struct {
unsigned long inuse;
+ spinlock_t io_lock;
} rc32434_wdt_device;
static struct integ __iomem *wdt_reg;
@@ -81,7 +83,9 @@ static int rc32434_wdt_set(int new_timeout)
return -EINVAL;
}
timeout = new_timeout;
+ spin_lock(&rc32434_wdt_device.io_lock);
writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare);
+ spin_unlock(&rc32434_wdt_device.io_lock);
return 0;
}
@@ -90,6 +94,8 @@ static void rc32434_wdt_start(void)
{
u32 or, nand;
+ spin_lock(&rc32434_wdt_device.io_lock);
+
/* zero the counter before enabling */
writel(0, &wdt_reg->wtcount);
@@ -112,20 +118,26 @@ static void rc32434_wdt_start(void)
SET_BITS(wdt_reg->wtc, or, nand);
+ spin_unlock(&rc32434_wdt_device.io_lock);
printk(KERN_INFO PFX "Started watchdog timer.\n");
}
static void rc32434_wdt_stop(void)
{
+ spin_lock(&rc32434_wdt_device.io_lock);
+
/* Disable WDT */
SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN);
+ spin_unlock(&rc32434_wdt_device.io_lock);
printk(KERN_INFO PFX "Stopped watchdog timer.\n");
}
static void rc32434_wdt_ping(void)
{
+ spin_lock(&rc32434_wdt_device.io_lock);
writel(0, &wdt_reg->wtcount);
+ spin_unlock(&rc32434_wdt_device.io_lock);
}
static int rc32434_wdt_open(struct inode *inode, struct file *file)
@@ -270,6 +282,8 @@ static int __devinit rc32434_wdt_probe(struct platform_device *pdev)
return -ENXIO;
}
+ spin_lock_init(&rc32434_wdt_device.io_lock);
+
/* Check that the heartbeat value is within it's range;
* if not reset to the default */
if (rc32434_wdt_set(timeout)) {