From: Christophe Roullier <christophe.roullier@st.com> To: <wim@linux-watchdog.org>, <linux@roeck-us.net>, <mcoquelin.stm32@gmail.com>, <alexandre.torgue@st.com> Cc: <linux-watchdog@vger.kernel.org>, <christophe.roullier@st.com>, <linux-kernel@vger.kernel.org>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-kernel@lists.infradead.org> Subject: [PATCH v3 1/1] drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe Date: Fri, 22 Nov 2019 14:22:46 +0100 [thread overview] Message-ID: <20191122132246.8473-1-christophe.roullier@st.com> (raw) 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> --- Changes since v2: According to Guenter removed intermediate variable I've tested some config and it is working as expected: Watchdog enable in Uboot + HANDLE_BOOT_ENABLE is not set + daemon watchdog in userland ON ==> No reset IWDG2 Watchdog enable in Uboot + HANDLE_BOOT_ENABLE is not set ==> Reset IWDG2 Watchdog enable in Uboot + HANDLE_BOOT_ENABLE=y ==> No reset IWDG2 Watchdog enable in Uboot + HANDLE_BOOT_ENABLE=y + daemon watchdog in userland ON puis OFF ==> Reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE is not set ==> No reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE=y ==> No reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE=y + daemon watchdog in userland ON ==> No reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE=y + daemon watchdog in userland ON puis OFF ==> Reset IWDG2 Thanks, Christophe drivers/watchdog/stm32_iwdg.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) 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; -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Christophe Roullier <christophe.roullier@st.com> To: <wim@linux-watchdog.org>, <linux@roeck-us.net>, <mcoquelin.stm32@gmail.com>, <alexandre.torgue@st.com> Cc: linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, christophe.roullier@st.com Subject: [PATCH v3 1/1] drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe Date: Fri, 22 Nov 2019 14:22:46 +0100 [thread overview] Message-ID: <20191122132246.8473-1-christophe.roullier@st.com> (raw) 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> --- Changes since v2: According to Guenter removed intermediate variable I've tested some config and it is working as expected: Watchdog enable in Uboot + HANDLE_BOOT_ENABLE is not set + daemon watchdog in userland ON ==> No reset IWDG2 Watchdog enable in Uboot + HANDLE_BOOT_ENABLE is not set ==> Reset IWDG2 Watchdog enable in Uboot + HANDLE_BOOT_ENABLE=y ==> No reset IWDG2 Watchdog enable in Uboot + HANDLE_BOOT_ENABLE=y + daemon watchdog in userland ON puis OFF ==> Reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE is not set ==> No reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE=y ==> No reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE=y + daemon watchdog in userland ON ==> No reset IWDG2 Watchdog disable in Uboot + HANDLE_BOOT_ENABLE=y + daemon watchdog in userland ON puis OFF ==> Reset IWDG2 Thanks, Christophe drivers/watchdog/stm32_iwdg.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) 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; -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2019-11-22 13:23 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-22 13:22 Christophe Roullier [this message] 2019-11-22 13:22 ` [PATCH v3 1/1] drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe Christophe Roullier 2019-11-22 18:15 ` Guenter Roeck 2019-11-22 18:15 ` Guenter Roeck
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