Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: Guenter Roeck <groeck7@gmail.com>
Subject: Re: [PATCH 2/5] watchdog: meson_gxbb_wdt: add timeout module param
To:     Artem Lapkin <email2tema@gmail.com>, narmstrong@baylibre.com
Cc:     wim@linux-watchdog.org, khilman@baylibre.com, jbrunet@baylibre.com,
        christianshewitt@gmail.com, martin.blumenstingl@googlemail.com,
        linux-watchdog@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        art@khadas.com, nick@khadas.com, gouwa@khadas.com
References: <20210623024429.1346349-1-art@khadas.com>
 <20210623024429.1346349-3-art@khadas.com>
From:   Guenter Roeck <linux@roeck-us.net>
Message-ID: <f4bac702-9121-fc84-e138-27f3f662f443@roeck-us.net>
Date:   Sun, 27 Jun 2021 08:32:40 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.8.1
MIME-Version: 1.0
In-Reply-To: <20210623024429.1346349-3-art@khadas.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 6/22/21 7:44 PM, Artem Lapkin wrote:
> Added timeout module param same as in other modules
> 
> Signed-off-by: Artem Lapkin <art@khadas.com>
> ---
>   drivers/watchdog/meson_gxbb_wdt.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
> index 3f86530c33b0..ecd1fc6f48ba 100644
> --- a/drivers/watchdog/meson_gxbb_wdt.c
> +++ b/drivers/watchdog/meson_gxbb_wdt.c
> @@ -29,6 +29,11 @@
>   #define GXBB_WDT_TCNT_SETUP_MASK		(BIT(16) - 1)
>   #define GXBB_WDT_TCNT_CNT_SHIFT			16
>   
> +static unsigned int timeout = DEFAULT_TIMEOUT;
> +module_param(timeout, uint, 0);
> +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds="
> +		 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
> +
>   struct meson_gxbb_wdt {
>   	void __iomem *reg_base;
>   	struct watchdog_device wdt_dev;
> @@ -174,7 +179,7 @@ static int meson_gxbb_wdt_probe(struct platform_device *pdev)
>   	data->wdt_dev.ops = &meson_gxbb_wdt_ops;
>   	data->wdt_dev.max_hw_heartbeat_ms = GXBB_WDT_TCNT_SETUP_MASK;
>   	data->wdt_dev.min_timeout = 1;
> -	data->wdt_dev.timeout = DEFAULT_TIMEOUT;
> +	data->wdt_dev.timeout = timeout;

This is wrong. A timeout module parameter should be set with a call to
watchdog_init_timeout(), the initial value should be 0, and data->wdt_dev.timeout
should be kept as-is. This ensures that the module parameter is validated.

Guenter

>   	watchdog_set_drvdata(&data->wdt_dev, data);
>   
>   	/* Setup with 1ms timebase */
>