Commit 1bfe8889 authored Sep 26, 2017 by Oleksij Rempel Committed by Wim Van Sebroeck Dec 28, 2017

watchdog: dw_wdt: add stop watchdog operation



The only way of stopping the watchdog is by resetting it.
Add the watchdog op for stopping the device and reset if
a reset line is provided.

At same time WDOG_HW_RUNNING should be remove from dw_wdt_start.
As commented by Guenter Roeck:
dw_wdt sets WDOG_HW_RUNNING in its open function. Result is
that the kref_get() in watchdog_open() won't be executed. But then
kref_put() in close will be called since the watchdog now does stop.
This causes the imbalance.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-watchdog@vger.kernel.org
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>

parent d4238aa4

drivers/watchdog/dw_wdt.c

+16 −2

Original line number	Diff line number	Diff line
		@@ -127,14 +127,27 @@ static int dw_wdt_start(struct watchdog_device *wdd)

		dw_wdt_set_timeout(wdd, wdd->timeout);

		set_bit(WDOG_HW_RUNNING, &wdd->status);

		writel(WDOG_CONTROL_REG_WDT_EN_MASK,
		dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);

		return 0;
		}

		static int dw_wdt_stop(struct watchdog_device *wdd)
		{
		struct dw_wdt *dw_wdt = to_dw_wdt(wdd);

		if (!dw_wdt->rst) {
		set_bit(WDOG_HW_RUNNING, &wdd->status);
		return 0;
		}

		reset_control_assert(dw_wdt->rst);
		reset_control_deassert(dw_wdt->rst);

		return 0;
		}

		static int dw_wdt_restart(struct watchdog_device *wdd,
		unsigned long action, void *data)
		{
		@@ -173,6 +186,7 @@ static const struct watchdog_info dw_wdt_ident = {
		static const struct watchdog_ops dw_wdt_ops = {
		.owner = THIS_MODULE,
		.start = dw_wdt_start,
		.stop = dw_wdt_stop,
		.ping = dw_wdt_ping,
		.set_timeout = dw_wdt_set_timeout,
		.get_timeleft = dw_wdt_get_timeleft,