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Message-ID: <d6c61a10-e671-3543-5653-ceb3d9ed60cf@roeck-us.net>
Date:   Wed, 23 Mar 2022 06:07:33 -0700
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Subject: Re: [PATCH v4] watchdog: imx2_wdg: Allow ping on suspend
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To:     Alistair Francis <alistair@alistair23.me>, shawnguo@kernel.org,
        linux-watchdog@vger.kernel.org, s.hauer@pengutronix.de,
        wim@linux-watchdog.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
Cc:     devicetree@vger.kernel.org, kernel@pengutronix.de,
        linux-imx@nxp.com, festevam@gmail.com, robh+dt@kernel.org
References: <20220323115752.360409-1-alistair@alistair23.me>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <20220323115752.360409-1-alistair@alistair23.me>
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On 3/23/22 04:57, Alistair Francis wrote:
> The i.MX watchdog cannot be disabled by software once it has been
> enabled. This means that it can't be stopped before suspend.
> 
> For systems that enter low power mode this is fine, as the watchdog will
> be automatically stopped by hardware in low power mode. Not all i.MX
> platforms support low power mode in the mainline kernel. For example the
> i.MX7D does not enter low power mode and so will be rebooted 2 minutes
> after entering sleep states.
> 
> This patch introduces a device tree property "fsl,ping-during-suspend"
> that can be used to enable ping on suspend support for these systems.
> 
> Signed-off-by: Alistair Francis <alistair@alistair23.me>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>

What is the difference to earlier versions ?

Guenter