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| author |   Christophe Roullier <christophe.roullier@st.com> | 2019-11-22 14:22:46 +0100 |
|---|---|---|
| committer |   Wim Van Sebroeck <wim@linux-watchdog.org> | 2020-01-27 15:55:44 +0100 |
| commit | 85fdc63fe256b595f923a69848cd99972ff446d8 (patch) | |
| tree | cc3b3f83622e2e47fc60d8e327cffe4a73e921b3 /drivers/watchdog | |
| parent | watchdog: sama5d4_wdt: addition of sam9x60 compatible watchdog (diff) | |
| download | linux-dev-85fdc63fe256b595f923a69848cd99972ff446d8.tar.xz linux-dev-85fdc63fe256b595f923a69848cd99972ff446d8.zip | |
drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe
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>
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/stm32_iwdg.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c index a3a329011a06..25188d6bbe15 100644 --- a/drivers/watchdog/stm32_iwdg.c +++ b/drivers/watchdog/stm32_iwdg.c @@ -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; |