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From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Ken Sloat <KSloat@aampglobal.com>
Cc: "nicolas.ferre@microchip.com" <nicolas.ferre@microchip.com>,
	"ludovic.desroches@microchip.com"
	<ludovic.desroches@microchip.com>,
	"wim@linux-watchdog.org" <wim@linux-watchdog.org>,
	"linux@roeck-us.net" <linux@roeck-us.net>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/1] watchdog: atmel: atmel-sama5d4-wdt: Disable watchdog on system suspend
Date: Thu, 20 Jun 2019 10:33:09 +0200
Message-ID: <20190620083309.GU23549@piout.net> (raw)
In-Reply-To: <20190614125310.29458-1-ksloat@aampglobal.com>

On 14/06/2019 12:53:22+0000, Ken Sloat wrote:
> From: Ken Sloat <ksloat@aampglobal.com>
> 
> Currently, the atmel-sama5d4-wdt continues to run after system suspend.
> Unless the system resumes within the watchdog timeout period so the
> userspace can kick it, the system will be reset. This change disables
> the watchdog on suspend if it is active and re-enables on resume. These
> actions occur during the late and early phases of suspend and resume
> respectively to minimize chances where a lock could occur while the
> watchdog is disabled.
> 
> Signed-off-by: Ken Sloat <ksloat@aampglobal.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> ---
>  Changes in v2:
>  -Consolidate resume and resume early statements.
> 
>  drivers/watchdog/sama5d4_wdt.c | 21 ++++++++++++++++++---
>  1 file changed, 18 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
> index 111695223aae..0d123f8cbcc6 100644
> --- a/drivers/watchdog/sama5d4_wdt.c
> +++ b/drivers/watchdog/sama5d4_wdt.c
> @@ -280,7 +280,17 @@ static const struct of_device_id sama5d4_wdt_of_match[] = {
>  MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
>  
>  #ifdef CONFIG_PM_SLEEP
> -static int sama5d4_wdt_resume(struct device *dev)
> +static int sama5d4_wdt_suspend_late(struct device *dev)
> +{
> +	struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
> +
> +	if (watchdog_active(&wdt->wdd))
> +		sama5d4_wdt_stop(&wdt->wdd);
> +
> +	return 0;
> +}
> +
> +static int sama5d4_wdt_resume_early(struct device *dev)
>  {
>  	struct sama5d4_wdt *wdt = dev_get_drvdata(dev);
>  
> @@ -291,12 +301,17 @@ static int sama5d4_wdt_resume(struct device *dev)
>  	 */
>  	sama5d4_wdt_init(wdt);
>  
> +	if (watchdog_active(&wdt->wdd))
> +		sama5d4_wdt_start(&wdt->wdd);
> +
>  	return 0;
>  }
>  #endif
>  
> -static SIMPLE_DEV_PM_OPS(sama5d4_wdt_pm_ops, NULL,
> -			 sama5d4_wdt_resume);
> +static const struct dev_pm_ops sama5d4_wdt_pm_ops = {
> +	SET_LATE_SYSTEM_SLEEP_PM_OPS(sama5d4_wdt_suspend_late,
> +			sama5d4_wdt_resume_early)
> +};
>  
>  static struct platform_driver sama5d4_wdt_driver = {
>  	.probe		= sama5d4_wdt_probe,
> -- 
> 2.17.1
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

  parent reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-14 12:53 Ken Sloat
2019-06-14 16:46 ` Guenter Roeck
2019-06-14 17:53   ` Ken Sloat
2019-06-14 18:08     ` Alexandre Belloni
2019-06-14 18:43       ` Ken Sloat
2019-06-14 20:33         ` Alexandre Belloni
2019-06-14 20:45           ` Ken Sloat
2019-06-15 14:22             ` Guenter Roeck
2019-06-20  8:33 ` Alexandre Belloni [this message]
2019-07-02 13:40 ` Guenter Roeck

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