1 files changed, 28 insertions, 14 deletions

diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index eb8fa25f8eb2..62be9e52a4de 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -105,34 +105,48 @@ static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
  * timeout module parameter (if it is valid value) or the timeout-sec property
  * (only if it is a valid value and the timeout_parm is out of bounds).
  * If none of them are valid then we keep the old value (which should normally
- * be the default timeout value).
+ * be the default timeout value). Note that for the module parameter, '0' means
+ * 'use default' while it is an invalid value for the timeout-sec property.
+ * It should simply be dropped if you want to use the default value then.
  *
- * A zero is returned on success and -EINVAL for failure.
+ * A zero is returned on success or -EINVAL if all provided values are out of
+ * bounds.
  */
 int watchdog_init_timeout(struct watchdog_device *wdd,
 				unsigned int timeout_parm, struct device *dev)
 {
+	const char *dev_str = wdd->parent ? dev_name(wdd->parent) :
+			      (const char *)wdd->info->identity;
 	unsigned int t = 0;
 	int ret = 0;
 
 	watchdog_check_min_max_timeout(wdd);
 
-	/* try to get the timeout module parameter first */
-	if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) {
-		wdd->timeout = timeout_parm;
-		return ret;
-	}
-	if (timeout_parm)
+	/* check the driver supplied value (likely a module parameter) first */
+	if (timeout_parm) {
+		if (!watchdog_timeout_invalid(wdd, timeout_parm)) {
+			wdd->timeout = timeout_parm;
+			return 0;
+		}
+		pr_err("%s: driver supplied timeout (%u) out of range\n",
+			dev_str, timeout_parm);
 		ret = -EINVAL;
+	}
 
 	/* try to get the timeout_sec property */
-	if (dev == NULL || dev->of_node == NULL)
-		return ret;
-	of_property_read_u32(dev->of_node, "timeout-sec", &t);
-	if (!watchdog_timeout_invalid(wdd, t) && t)
-		wdd->timeout = t;
-	else
+	if (dev && dev->of_node &&
+	    of_property_read_u32(dev->of_node, "timeout-sec", &t) == 0) {
+		if (t && !watchdog_timeout_invalid(wdd, t)) {
+			wdd->timeout = t;
+			return 0;
+		}
+		pr_err("%s: DT supplied timeout (%u) out of range\n", dev_str, t);
 		ret = -EINVAL;
+	}
+
+	if (ret < 0 && wdd->timeout)
+		pr_warn("%s: falling back to default timeout (%u)\n", dev_str,
+			wdd->timeout);
 
 	return ret;
 }