watchdog (iTCO_wdt) heartbeat/timeout value is ignored after suspend-to-{RAM,disk}

The iTCO_wdt watchdog state and timeout (heartbeat) need to be
restored after resume. Use pm_ops to do this.

Signed-off-by: David A. Madore <david+



old/drivers/watchdog/iTCO_wdt.c 2012-04-13 18:42:02.000000000 +0200
+++ new/drivers/watchdog/iTCO_wdt.c 2012-04-15 20:43:39.609718697 +0200
@@ -56,6 +56,7 @@
#include <linux/kernel.h> /* For printk/panic/... */
#include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV
(WATCHDOG_MINOR) */
+#include <linux/pm.h> /* For struct dev_pm_ops */
#include <linux/watchdog.h> /* For the watchdog specific items */
#include <linux/init.h> /* For __init/__exit/... */
#include <linux/fs.h> /* For file operations */
@@ -400,6 +401,8 @@ static struct { /* this is private data
spinlock_t io_lock;
/* the PCI-device */
struct pci_dev *pdev;
+ /* whether the timer is started */
+ char is_started;
} iTCO_wdt_private;

/* the watchdog platform device */
@@ -506,6 +509,7 @@ static int iTCO_wdt_start(void)
val &= 0xf7ff;
outw(val, TCO1_CNT);
val = inw(TCO1_CNT);
+ iTCO_wdt_private.is_started = 1;
spin_unlock(&iTCO_wdt_private.io_lock);

if (val & 0x0800)
@@ -530,6 +534,8 @@ static int iTCO_wdt_stop(void)
/* Set the NO_REBOOT bit to prevent later reboots, just for sure */
iTCO_wdt_set_NO_REBOOT_bit();

+ iTCO_wdt_private.is_started = 0;
+
spin_unlock(&iTCO_wdt_private.io_lock);

if ((val & 0x0800) == 0)
@@ -965,6 +971,35 @@ static void iTCO_wdt_shutdown(struct pla
iTCO_wdt_stop();
}

+#ifdef CONFIG_PM
+static int iTCO_wdt_suspend(struct device *dev)
+{
+ char save_is_started = iTCO_wdt_private.is_started;
+ iTCO_wdt_stop();
+ iTCO_wdt_private.is_started = save_is_started;
+ return 0;
+}
+
+static int iTCO_wdt_resume(struct device *dev)
+{
+ iTCO_wdt_set_heartbeat(heartbeat);
+ iTCO_wdt_keepalive();
+ if (iTCO_wdt_private.is_started) {
+ printk(KERN_INFO PFX "Watchdog restarted after resume.");
+ iTCO_wdt_start();
+ } else {
+ printk(KERN_INFO PFX "Watchdog stopped after resume.");
+ iTCO_wdt_stop();
+ }
+ return 0;
+}
+
+static const struct dev_pm_ops iTCO_wdt_pm_ops = {
+ .suspend = iTCO_wdt_suspend,
+ .resume = iTCO_wdt_resume,
+};
+#endif /* CONFIG_PM */
+
static struct platform_driver iTCO_wdt_driver = {
.probe = iTCO_wdt_probe,
.remove = __devexit_p(iTCO_wdt_remove),
@@ -972,6 +1007,9 @@ static struct platform_driver iTCO_wdt_d
.driver = {
.owner = THIS_MODULE,
.name = DRV_NAME,
+#ifdef CONFIG_PM
+ .pm = &iTCO_wdt_pm_ops,
+#endif /* CONFIG_PM */
},
};


David A. Madore
( http://www.madore.org/~david/ )
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