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[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>
This commit is contained in:
Wim Van Sebroeck 2006-09-10 12:48:15 +02:00
parent f676449785
commit 99d2853ac9
1 changed files with 12 additions and 0 deletions
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12
drivers/char/watchdog/pnx4008_wdt.c
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@ -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;