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Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <88eb9941-7bf4-3220-ff8a-7e9b3f4bb01b@roeck-us.net>
Date:   Mon, 28 Nov 2022 20:53:27 -0800
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Subject: Re: [PATCH 1/2] watchdog: rzg2l_wdt: Issue a reset before we put the
 PM clocks
Content-Language: en-US
To:     Fabrizio Castro <fabrizio.castro.jz@renesas.com>,
        Wim Van Sebroeck <wim@linux-watchdog.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Geert Uytterhoeven <geert+renesas@glider.be>
Cc:     Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
        Biju Das <biju.das.jz@bp.renesas.com>,
        linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
        Chris Paterson <Chris.Paterson2@renesas.com>,
        Biju Das <biju.das@bp.renesas.com>,
        linux-renesas-soc@vger.kernel.org,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Jacopo Mondi <jacopo@jmondi.org>
References: <20221117114907.138583-1-fabrizio.castro.jz@renesas.com>
 <20221117114907.138583-2-fabrizio.castro.jz@renesas.com>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <20221117114907.138583-2-fabrizio.castro.jz@renesas.com>
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On 11/17/22 03:49, Fabrizio Castro wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> On RZ/Five SoC it was observed that setting timeout (to say 1 sec) wouldn't
> reset the system.
> 
> The procedure described in the HW manual (Procedure for Activating Modules)
> for activating the target module states we need to start supply of the
> clock module before applying the reset signal. This patch makes sure we
> follow the same procedure to clear the registers of the WDT module, fixing
> the issues seen on RZ/Five SoC.
> 
> While at it re-used rzg2l_wdt_stop() in rzg2l_wdt_set_timeout() as it has
> the same function calls.
> 
> Fixes: 4055ee81009e ("watchdog: rzg2l_wdt: Add set_timeout callback")
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>   drivers/watchdog/rzg2l_wdt.c | 10 ++++------
>   1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
> index 974a4194a8fd..ceca42db0837 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -115,25 +115,23 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
>   {
>   	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
>   
> -	pm_runtime_put(wdev->parent);
>   	reset_control_reset(priv->rstc);
> +	pm_runtime_put(wdev->parent);
>   
>   	return 0;
>   }
>   
>   static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout)
>   {
> -	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> -
>   	wdev->timeout = timeout;
>   
>   	/*
>   	 * If the watchdog is active, reset the module for updating the WDTSET
> -	 * register so that it is updated with new timeout values.
> +	 * register by calling rzg2l_wdt_stop() (which internally calls reset_control_reset()
> +	 * to reset the module) so that it is updated with new timeout values.
>   	 */
>   	if (watchdog_active(wdev)) {
> -		pm_runtime_put(wdev->parent);
> -		reset_control_reset(priv->rstc);
> +		rzg2l_wdt_stop(wdev);
>   		rzg2l_wdt_start(wdev);
>   	}
>