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authorWim Van Sebroeck <wim@iguana.be>2006-09-10 12:48:15 +0200
committerWim Van Sebroeck <wim@iguana.be>2006-10-02 23:05:28 +0200
commit99d2853ac953900962d8191788060e80766eb214 (patch)
tree318eb3eb9dbf15059c81bc201e9c83599b60fbf5 /drivers/char/watchdog
parentf676449785d333078acb60ccf2046d0d3c59548f (diff)
[WATCHDOG] pnx4008_wdt.c - spinlock fixes.
Add io spinlocks to prevent possible race conditions between start and stop operations that are issued from different child processes where the master process opened /dev/watchdog. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/char/watchdog')
-rw-r--r--drivers/char/watchdog/pnx4008_wdt.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/char/watchdog/pnx4008_wdt.c b/drivers/char/watchdog/pnx4008_wdt.c
index 465dfd3ba61a..359168e63c1d 100644
--- a/drivers/char/watchdog/pnx4008_wdt.c
+++ b/drivers/char/watchdog/pnx4008_wdt.c
@@ -28,6 +28,7 @@
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
+#include <linux/spinlock.h>
#include <asm/hardware.h>
#include <asm/uaccess.h>
@@ -80,6 +81,7 @@
static int nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = DEFAULT_HEARTBEAT;
+static spinlock_t io_lock;
static unsigned long wdt_status;
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
@@ -94,6 +96,8 @@ struct clk *wdt_clk;
static void wdt_enable(void)
{
+ spin_lock(&io_lock);
+
if (wdt_clk)
clk_set_rate(wdt_clk, 1);
@@ -113,13 +117,19 @@ static void wdt_enable(void)
__raw_writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
/*enable counter, stop when debugger active */
__raw_writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
+
+ spin_unlock(&io_lock);
}
static void wdt_disable(void)
{
+ spin_lock(&io_lock);
+
__raw_writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
if (wdt_clk)
clk_set_rate(wdt_clk, 0);
+
+ spin_unlock(&io_lock);
}
static int pnx4008_wdt_open(struct inode *inode, struct file *file)
@@ -248,6 +258,8 @@ static int pnx4008_wdt_probe(struct platform_device *pdev)
int ret = 0, size;
struct resource *res;
+ spin_lock_init(&io_lock);
+
if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
heartbeat = DEFAULT_HEARTBEAT;