4.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marco Felsch m.felsch@pengutronix.de
[ Upstream commit 44ee54aabfdb3b35866ed909bde3ab01e9679385 ]
The DA9063 watchdog has only one register field to store the timeout value and to enable the watchdog. The watchdog gets enabled if the value is not zero. There is no issue if the watchdog is already running but it leads into problems if the watchdog is disabled.
If the watchdog is disabled and only the timeout value should be prepared the watchdog gets enabled too. Add a check to get the current watchdog state and update the watchdog timeout value on hw-side only if the watchdog is already active.
Fixes: 5e9c16e37608 ("watchdog: Add DA9063 PMIC watchdog driver.") Signed-off-by: Marco Felsch m.felsch@pengutronix.de Reviewed-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Wim Van Sebroeck wim@linux-watchdog.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/watchdog/da9063_wdt.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)
--- a/drivers/watchdog/da9063_wdt.c +++ b/drivers/watchdog/da9063_wdt.c @@ -99,10 +99,23 @@ static int da9063_wdt_set_timeout(struct { struct da9063 *da9063 = watchdog_get_drvdata(wdd); unsigned int selector; - int ret; + int ret = 0;
selector = da9063_wdt_timeout_to_sel(timeout); - ret = _da9063_wdt_set_timeout(da9063, selector); + + /* + * There are two cases when a set_timeout() will be called: + * 1. The watchdog is off and someone wants to set the timeout for the + * further use. + * 2. The watchdog is already running and a new timeout value should be + * set. + * + * The watchdog can't store a timeout value not equal zero without + * enabling the watchdog, so the timeout must be buffered by the driver. + */ + if (watchdog_active(wdd)) + ret = _da9063_wdt_set_timeout(da9063, selector); + if (ret) dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n", ret);