commit 2accf320786210db92f36866cc71fa894f510a4a
author Wolfram Sang <wsa+renesas@sang-engineering.com> Fri Oct 07 15:41:38 2016 +0300
committer Wim Van Sebroeck <wim@iguana.be> Sat Oct 08 10:27:27 2016 +0200
tree dbdd5b499043fffc3741974608b13f0c042be49b
parent 89873a711dd20b614abb6e4038fb4b5462f4c701

watchdog: softdog: implement pretimeout support

Give devices which do not have hardware support for pretimeout at least a
software version of it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/softdog.c

diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c
index 1ae469e..c7bdc98 100644
--- a/drivers/watchdog/softdog.c
+++ b/drivers/watchdog/softdog.c
@@ -72,10 +72,27 @@
 static struct timer_list softdog_ticktock =
 		TIMER_INITIALIZER(softdog_fire, 0, 0);
 
+static struct watchdog_device softdog_dev;
+
+static void softdog_pretimeout(unsigned long data)
+{
+	watchdog_notify_pretimeout(&softdog_dev);
+}
+
+static struct timer_list softdog_preticktock =
+		TIMER_INITIALIZER(softdog_pretimeout, 0, 0);
+
 static int softdog_ping(struct watchdog_device *w)
 {
 	if (!mod_timer(&softdog_ticktock, jiffies + (w->timeout * HZ)))
 		__module_get(THIS_MODULE);
+
+	if (w->pretimeout)
+		mod_timer(&softdog_preticktock, jiffies +
+			  (w->timeout - w->pretimeout) * HZ);
+	else
+		del_timer(&softdog_preticktock);
+
 	return 0;
 }
 
@@ -84,12 +101,15 @@
 	if (del_timer(&softdog_ticktock))
 		module_put(THIS_MODULE);
 
+	del_timer(&softdog_preticktock);
+
 	return 0;
 }
 
 static struct watchdog_info softdog_info = {
 	.identity = "Software Watchdog",
-	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
+		   WDIOF_PRETIMEOUT,
 };
 
 static const struct watchdog_ops softdog_ops = {