From: Vignesh Raghavendra <vigneshr@ti.com> To: Wim Van Sebroeck <wim@linux-watchdog.org>, Guenter Roeck <linux@roeck-us.net> Cc: Manorit Chawdhry <m-chawdhry@ti.com>, <linux-watchdog@vger.kernel.org>, <linux-kernel@vger.kernel.org>, Vignesh Raghavendra <vigneshr@ti.com>, <linux-arm-kernel@lists.infradead.org> Subject: [PATCH v3] watchdog: rti_wdt: Drop runtime pm reference count when watchdog is unused Date: Wed, 13 Dec 2023 19:31:10 +0530 [thread overview] Message-ID: <20231213140110.938129-1-vigneshr@ti.com> (raw) Call runtime_pm_put*() if watchdog is not already started during probe and re enable it in watchdog start as required. On K3 SoCs, watchdogs and their corresponding CPUs are under same power-domain, so if the reference count of unused watchdogs aren't dropped, it will lead to CPU hotplug failures as Device Management firmware won't allow to turn off the power-domain due to dangling reference count. Fixes: 2d63908bdbfb ("watchdog: Add K3 RTI watchdog support") Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Manorit Chawdhry <m-chawdhry@ti.com> --- v3: Reword commit message to expand non std acronyms Collect Reviewed-by and Tested-by tags No code change v2: https://lore.kernel.org/r/20231122041642.2015936-1-vigneshr@ti.com v2: * Drop 1/2 (will be posted along with runtime_pm callbacks) * Use pm_runtime_resume_and_get() instead of pm_runtime_get_sync() which takes care of err handling v1: https://lore.kernel.org/r/20231110100726.2930218-1-vigneshr@ti.com drivers/watchdog/rti_wdt.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 8e1be7ba0103..9215793a1c81 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -77,6 +77,11 @@ static int rti_wdt_start(struct watchdog_device *wdd) { u32 timer_margin; struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd); + int ret; + + ret = pm_runtime_resume_and_get(wdd->parent); + if (ret) + return ret; /* set timeout period */ timer_margin = (u64)wdd->timeout * wdt->freq; @@ -343,6 +348,9 @@ static int rti_wdt_probe(struct platform_device *pdev) if (last_ping) watchdog_set_last_hw_keepalive(wdd, last_ping); + if (!watchdog_hw_running(wdd)) + pm_runtime_put_sync(&pdev->dev); + return 0; err_iomap: @@ -357,7 +365,10 @@ static void rti_wdt_remove(struct platform_device *pdev) struct rti_wdt_device *wdt = platform_get_drvdata(pdev); watchdog_unregister_device(&wdt->wdd); - pm_runtime_put(&pdev->dev); + + if (!pm_runtime_suspended(&pdev->dev)) + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); } -- 2.43.0
WARNING: multiple messages have this Message-ID (diff)
From: Vignesh Raghavendra <vigneshr@ti.com> To: Wim Van Sebroeck <wim@linux-watchdog.org>, Guenter Roeck <linux@roeck-us.net> Cc: Manorit Chawdhry <m-chawdhry@ti.com>, <linux-watchdog@vger.kernel.org>, <linux-kernel@vger.kernel.org>, Vignesh Raghavendra <vigneshr@ti.com>, <linux-arm-kernel@lists.infradead.org> Subject: [PATCH v3] watchdog: rti_wdt: Drop runtime pm reference count when watchdog is unused Date: Wed, 13 Dec 2023 19:31:10 +0530 [thread overview] Message-ID: <20231213140110.938129-1-vigneshr@ti.com> (raw) Call runtime_pm_put*() if watchdog is not already started during probe and re enable it in watchdog start as required. On K3 SoCs, watchdogs and their corresponding CPUs are under same power-domain, so if the reference count of unused watchdogs aren't dropped, it will lead to CPU hotplug failures as Device Management firmware won't allow to turn off the power-domain due to dangling reference count. Fixes: 2d63908bdbfb ("watchdog: Add K3 RTI watchdog support") Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Manorit Chawdhry <m-chawdhry@ti.com> --- v3: Reword commit message to expand non std acronyms Collect Reviewed-by and Tested-by tags No code change v2: https://lore.kernel.org/r/20231122041642.2015936-1-vigneshr@ti.com v2: * Drop 1/2 (will be posted along with runtime_pm callbacks) * Use pm_runtime_resume_and_get() instead of pm_runtime_get_sync() which takes care of err handling v1: https://lore.kernel.org/r/20231110100726.2930218-1-vigneshr@ti.com drivers/watchdog/rti_wdt.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 8e1be7ba0103..9215793a1c81 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -77,6 +77,11 @@ static int rti_wdt_start(struct watchdog_device *wdd) { u32 timer_margin; struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd); + int ret; + + ret = pm_runtime_resume_and_get(wdd->parent); + if (ret) + return ret; /* set timeout period */ timer_margin = (u64)wdd->timeout * wdt->freq; @@ -343,6 +348,9 @@ static int rti_wdt_probe(struct platform_device *pdev) if (last_ping) watchdog_set_last_hw_keepalive(wdd, last_ping); + if (!watchdog_hw_running(wdd)) + pm_runtime_put_sync(&pdev->dev); + return 0; err_iomap: @@ -357,7 +365,10 @@ static void rti_wdt_remove(struct platform_device *pdev) struct rti_wdt_device *wdt = platform_get_drvdata(pdev); watchdog_unregister_device(&wdt->wdd); - pm_runtime_put(&pdev->dev); + + if (!pm_runtime_suspended(&pdev->dev)) + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); } -- 2.43.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2023-12-13 14:01 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-12-13 14:01 Vignesh Raghavendra [this message] 2023-12-13 14:01 ` [PATCH v3] watchdog: rti_wdt: Drop runtime pm reference count when watchdog is unused Vignesh Raghavendra
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