watchdog: intel-mid_wdt: Keep watchdog running

Firmware followed by bootloader leaves watchdog running.

Keep it running in the driver.

User will not need any additional options to reboot in case of panic
during boot.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.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/intel-mid_wdt.c

@@ -147,8 +147,21 @@ static int mid_wdt_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	/* Make sure the watchdog is not running */
-	wdt_stop(wdt_dev);
+	/*
+	 * The firmware followed by U-Boot leaves the watchdog running
+	 * with the default threshold which may vary. When we get here
+	 * we should make a decision to prevent any side effects before
+	 * user space daemon will take care of it. The best option,
+	 * taking into consideration that there is no way to read values
+	 * back from hardware, is to enforce watchdog being run with
+	 * deterministic values.
+	 */
+	ret = wdt_start(wdt_dev);
+	if (ret)
+		return ret;
+
+	/* Make sure the watchdog is serviced */
+	set_bit(WDOG_HW_RUNNING, &wdt_dev->status);
 
 	ret = devm_watchdog_register_device(&pdev->dev, wdt_dev);
 	if (ret) {