[WATCHDOG] rc32434_wdt: add spin_locking
Add spin_locks to prevent races.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c
index eee2992..bffd4a2 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 @@
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 @@
{
u32 or, nand;
+ spin_lock(&rc32434_wdt_device.io_lock);
+
/* zero the counter before enabling */
writel(0, &wdt_reg->wtcount);
@@ -112,20 +118,26 @@
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 @@
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)) {