| From a6b2af102ad6d99d713071125ec01d66496acf0a Mon Sep 17 00:00:00 2001 |
| From: Christophe Roullier <christophe.roullier@st.com> |
| Date: Fri, 22 Nov 2019 14:22:46 +0100 |
| Subject: [PATCH] drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe |
| |
| commit 85fdc63fe256b595f923a69848cd99972ff446d8 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: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c |
| index d569a3634d9b..8caf732b9133 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) { |
| dev_err(dev, "failed to register watchdog device\n"); |
| -- |
| 2.7.4 |
| |
