Re: [PATCH v3 03/12] watchdog: s3c2410: Fail probe if can't find valid timeout

From: Guenter Roeck <linux@roeck-us.net>
To: Sam Protsenko <semen.protsenko@linaro.org>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
	linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org
Subject: Re: [PATCH v3 03/12] watchdog: s3c2410: Fail probe if can't find valid timeout
Date: Wed, 17 Nov 2021 05:34:38 -0800	[thread overview]
Message-ID: <20211117133438.GC2435591@roeck-us.net> (raw)
In-Reply-To: <20211107202943.8859-4-semen.protsenko@linaro.org>

On Sun, Nov 07, 2021 at 10:29:34PM +0200, Sam Protsenko wrote:
> Driver can't work properly if there no valid timeout was found in
> s3c2410wdt_set_heartbeat(). Ideally, that function should be reworked in
> a way that it's always able to find some valid timeout. As a temporary
> solution let's for now just fail the driver probe in case the valid
> timeout can't be found in s3c2410wdt_set_heartbeat() function.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Suggested-by: Guenter Roeck <linux@roeck-us.net>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

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

> ---
> Changes in v3:
>   - Added R-b tag by Krzysztof Kozlowski
> 
> Changes in v2:
>   - (none): it's a new patch
> 
>  drivers/watchdog/s3c2410_wdt.c | 21 ++++++++++-----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 2395f353e52d..00421cf22556 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -515,7 +515,6 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>  	struct s3c2410_wdt *wdt;
>  	struct resource *wdt_irq;
>  	unsigned int wtcon;
> -	int started = 0;
>  	int ret;
>  
>  	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
> @@ -581,15 +580,15 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>  	ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
>  					wdt->wdt_device.timeout);
>  	if (ret) {
> -		started = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
> -					S3C2410_WATCHDOG_DEFAULT_TIME);
> -
> -		if (started == 0)
> -			dev_info(dev,
> -				 "tmr_margin value out of range, default %d used\n",
> +		ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device,
> +					       S3C2410_WATCHDOG_DEFAULT_TIME);
> +		if (ret == 0) {
> +			dev_warn(dev, "tmr_margin value out of range, default %d used\n",
>  				 S3C2410_WATCHDOG_DEFAULT_TIME);
> -		else
> -			dev_info(dev, "default timer value is out of range, cannot start\n");
> +		} else {
> +			dev_err(dev, "failed to use default timeout\n");
> +			goto err_cpufreq;
> +		}
>  	}
>  
>  	ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0,
> @@ -613,10 +612,10 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>  	if (ret < 0)
>  		goto err_unregister;
>  
> -	if (tmr_atboot && started == 0) {
> +	if (tmr_atboot) {
>  		dev_info(dev, "starting watchdog timer\n");
>  		s3c2410wdt_start(&wdt->wdt_device);
> -	} else if (!tmr_atboot) {
> +	} else {
>  		/* if we're not enabling the watchdog, then ensure it is
>  		 * disabled if it has been left running from the bootloader
>  		 * or other source */
> -- 
> 2.30.2
>