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drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe 

commit 85fdc63fe2 upstream.

If the watchdog hardware is already enabled during the boot process,
when the Linux watchdog driver loads, it should start/reset the watchdog
and tell the watchdog framework. As a result, ping can be generated from
the watchdog framework (if CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED is set),
until the userspace watchdog daemon takes over control

Fixes:4332d113c66a ("watchdog: Add STM32 IWDG driver")

Signed-off-by: Christophe Roullier <christophe.roullier@st.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191122132246.8473-1-christophe.roullier@st.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Christophe Roullier 2019-11-22 14:22:46 +01:00 committed by Greg Kroah-Hartman
parent 8dfa118376
commit 30dd20c6d0
1 changed files with 18 additions and 0 deletions
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18
drivers/watchdog/stm32_iwdg.c
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@ -262,6 +262,24 @@ static int stm32_iwdg_probe(struct platform_device *pdev)
watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT);
watchdog_init_timeout(wdd, 0, dev);
/*
* In case of CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED is set
* (Means U-Boot/bootloaders leaves the watchdog running)
* 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.
*/
if (IS_ENABLED(CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED)) {
ret = stm32_iwdg_start(wdd);
if (ret)
return ret;
/* Make sure the watchdog is serviced */
set_bit(WDOG_HW_RUNNING, &wdd->status);
}
ret = devm_watchdog_register_device(dev, wdd);
if (ret)
return ret;