This is a note to let you know that I've just added the patch titled

watchdog: dw_wdt: add stop watchdog operation

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: watchdog-dw_wdt-add-stop-watchdog-operation.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Mon Apr 9 10:16:32 CEST 2018

From: Oleksij Rempel o.rempel@pengutronix.de Date: Tue, 26 Sep 2017 08:11:22 +0200 Subject: watchdog: dw_wdt: add stop watchdog operation

From: Oleksij Rempel o.rempel@pengutronix.de

[ Upstream commit 1bfe8889380890efe4943d125124f5a7b48571b0 ]

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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/watchdog/dw_wdt.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)

--- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -127,14 +127,27 @@ static int dw_wdt_start(struct watchdog_

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 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,

Patches currently in stable-queue which might be from o.rempel@pengutronix.de are

queue-4.15/watchdog-dw_wdt-add-stop-watchdog-operation.patch