From: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> To: wim@linux-watchdog.org, linux@roeck-us.net, shawnguo@kernel.org Cc: linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, grzegorz.jaszczyk@linaro.org, Michal Koziel <michal.koziel@emlogic.no> Subject: [PATCH 2/2] watchdog: imx2_wdg: notify wdog subsystem about wdog suspend/resume Date: Tue, 15 Jun 2021 14:39:04 +0200 [thread overview] Message-ID: <20210615123904.2568052-3-grzegorz.jaszczyk@linaro.org> (raw) In-Reply-To: <20210615123904.2568052-1-grzegorz.jaszczyk@linaro.org> Suspend routine disables wdog clk. Nevertheless, the watchdog subsystem is not aware of that and can still try to ping wdog through watchdog_ping_work. In order to prevent such condition and therefore prevent from system hang (caused by the wdog register access issued while the wdog clock is disabled) take advantage of watchdog_dev_suspend/resume routines which will take care of watchdog ping worker cancel and restore. Additionally remove hw ping from suspend/resume since it will be issued by watchdog_dev_suspend/resume routines. Signed-off-by: Michal Koziel <michal.koziel@emlogic.no> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> --- drivers/watchdog/imx2_wdt.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index b84f80f7d342..24e3a4d2b529 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -348,6 +348,17 @@ static int __maybe_unused imx2_wdt_suspend(struct device *dev) { struct watchdog_device *wdog = dev_get_drvdata(dev); struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); + int ret; + + /* + * Before disabling clk we need to notify wdog subsystem that HW wdog + * is being suspended. This e.g. prevents watchdog_ping_work to fire + * when the clk is disabled, which would result with system hang caused + * by wdog register access while wdog clock is disabled. + */ + ret = watchdog_dev_suspend(wdog); + if (ret) + return ret; /* The watchdog IP block is running */ if (imx2_wdt_is_running(wdev)) { @@ -356,7 +367,6 @@ static int __maybe_unused imx2_wdt_suspend(struct device *dev) * during resume. */ __imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); - imx2_wdt_ping(wdog); } clk_disable_unprepare(wdev->clk); @@ -383,12 +393,12 @@ static int __maybe_unused imx2_wdt_resume(struct device *dev) */ imx2_wdt_setup(wdog); } - if (imx2_wdt_is_running(wdev)) { + if (imx2_wdt_is_running(wdev)) imx2_wdt_set_timeout(wdog, wdog->timeout); - imx2_wdt_ping(wdog); - } - return 0; + ret = watchdog_dev_resume(wdog); + + return ret; } static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend, -- 2.29.0
WARNING: multiple messages have this Message-ID (diff)
From: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> To: wim@linux-watchdog.org, linux@roeck-us.net, shawnguo@kernel.org Cc: linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, grzegorz.jaszczyk@linaro.org, Michal Koziel <michal.koziel@emlogic.no> Subject: [PATCH 2/2] watchdog: imx2_wdg: notify wdog subsystem about wdog suspend/resume Date: Tue, 15 Jun 2021 14:39:04 +0200 [thread overview] Message-ID: <20210615123904.2568052-3-grzegorz.jaszczyk@linaro.org> (raw) In-Reply-To: <20210615123904.2568052-1-grzegorz.jaszczyk@linaro.org> Suspend routine disables wdog clk. Nevertheless, the watchdog subsystem is not aware of that and can still try to ping wdog through watchdog_ping_work. In order to prevent such condition and therefore prevent from system hang (caused by the wdog register access issued while the wdog clock is disabled) take advantage of watchdog_dev_suspend/resume routines which will take care of watchdog ping worker cancel and restore. Additionally remove hw ping from suspend/resume since it will be issued by watchdog_dev_suspend/resume routines. Signed-off-by: Michal Koziel <michal.koziel@emlogic.no> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> --- drivers/watchdog/imx2_wdt.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index b84f80f7d342..24e3a4d2b529 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -348,6 +348,17 @@ static int __maybe_unused imx2_wdt_suspend(struct device *dev) { struct watchdog_device *wdog = dev_get_drvdata(dev); struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); + int ret; + + /* + * Before disabling clk we need to notify wdog subsystem that HW wdog + * is being suspended. This e.g. prevents watchdog_ping_work to fire + * when the clk is disabled, which would result with system hang caused + * by wdog register access while wdog clock is disabled. + */ + ret = watchdog_dev_suspend(wdog); + if (ret) + return ret; /* The watchdog IP block is running */ if (imx2_wdt_is_running(wdev)) { @@ -356,7 +367,6 @@ static int __maybe_unused imx2_wdt_suspend(struct device *dev) * during resume. */ __imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); - imx2_wdt_ping(wdog); } clk_disable_unprepare(wdev->clk); @@ -383,12 +393,12 @@ static int __maybe_unused imx2_wdt_resume(struct device *dev) */ imx2_wdt_setup(wdog); } - if (imx2_wdt_is_running(wdev)) { + if (imx2_wdt_is_running(wdev)) imx2_wdt_set_timeout(wdog, wdog->timeout); - imx2_wdt_ping(wdog); - } - return 0; + ret = watchdog_dev_resume(wdog); + + return ret; } static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend, -- 2.29.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-06-15 12:39 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-15 12:39 [PATCH 0/2] introduce watchdog_dev_suspend/resume Grzegorz Jaszczyk 2021-06-15 12:39 ` Grzegorz Jaszczyk 2021-06-15 12:39 ` [PATCH 1/2] watchdog: " Grzegorz Jaszczyk 2021-06-15 12:39 ` Grzegorz Jaszczyk 2021-06-15 14:18 ` Guenter Roeck 2021-06-15 14:18 ` Guenter Roeck 2021-06-16 13:59 ` Grzegorz Jaszczyk 2021-06-16 13:59 ` Grzegorz Jaszczyk 2021-06-16 17:57 ` Guenter Roeck 2021-06-16 17:57 ` Guenter Roeck 2021-06-16 23:21 ` kernel test robot 2021-06-16 23:21 ` kernel test robot 2021-06-16 23:21 ` kernel test robot 2021-06-15 12:39 ` Grzegorz Jaszczyk [this message] 2021-06-15 12:39 ` [PATCH 2/2] watchdog: imx2_wdg: notify wdog subsystem about wdog suspend/resume Grzegorz Jaszczyk
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20210615123904.2568052-3-grzegorz.jaszczyk@linaro.org \ --to=grzegorz.jaszczyk@linaro.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-watchdog@vger.kernel.org \ --cc=linux@roeck-us.net \ --cc=michal.koziel@emlogic.no \ --cc=shawnguo@kernel.org \ --cc=wim@linux-watchdog.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.