[PATCH] Watchdog: Fix for settimeout issue

Some devices have a fixed minimum elapse time and a ping before this
elapse time causes error condition. This patch fix this issue in the
settimeout operation.

drivers/watchdog/watchdog_dev.c | 7 ++++++-
include/linux/watchdog.h | 3 +++
2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 8558da9..fb6076c 100644
a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -41,6 +41,7 @@
#include <linux/miscdevice.h> /* For handling misc devices */
#include <linux/init.h> /* For __init/__exit/... */
#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
+#include <linux/delay.h> /* For delay (like mdelay) */

/* make sure we only register one /dev/watchdog device */
static unsigned long watchdog_dev_busy;
@@ -228,7 +229,11 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
return err;
/* If the watchdog is active then we send a keepalive ping
* to make sure that the watchdog keep's running (and if
- * possible that it takes the new timeout) */
+ * possible that it takes the new timeout) Also we care
+ * for watchdog which needs min elapse time before a ping.
+ */
+ if (wdd->min_elapse_time)
+ mdelay(wdd->min_elapse_time);
watchdog_ping(wdd);
/* Fall */
case WDIOC_GETTIMEOUT:
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index ac40716..37d25b8 100644
a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -95,6 +95,8 @@ struct watchdog_ops {
* @timeout: The watchdog devices timeout value.
* @min_timeout:The watchdog devices minimum timeout value.
* @max_timeout:The watchdog devices maximum timeout value.
+ * @min_elapse_time: The watchdog devices minimum elapse time before
+ * the ping.
* @driver-data:Pointer to the drivers private data.
* @status: Field that contains the devices internal status bits.
*
@@ -111,6 +113,7 @@ struct watchdog_device {
unsigned int timeout;
unsigned int min_timeout;
unsigned int max_timeout;
+ unsigned int min_elapse_time;
void *driver_data;
unsigned long status;
/* Bit numbers for status flags */


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