Sender: Guenter Roeck <groeck7@gmail.com>
Subject: Re: [PATCH v4 8/9] watchdog: max77620: add comment to clarify
 set_timeout procedure
To:     Luca Ceresoli <luca@lucaceresoli.net>
Cc:     linux-kernel@vger.kernel.org, Lee Jones <lee.jones@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Alessandro Zummo <a.zummo@towertech.it>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Wim Van Sebroeck <wim@linux-watchdog.org>,
        devicetree@vger.kernel.org, linux-rtc@vger.kernel.org,
        linux-watchdog@vger.kernel.org,
        Chiwoong Byun <woong.byun@samsung.com>,
        Laxman Dewangan <ldewangan@nvidia.com>,
        Randy Dunlap <rdunlap@infradead.org>
References: <20211120155707.4019487-1-luca@lucaceresoli.net>
 <20211120155707.4019487-9-luca@lucaceresoli.net>
 <20211129160414.GA3014810@roeck-us.net>
 <0e08d0e0-489c-342b-4fa4-d4457af20a65@lucaceresoli.net>
From:   Guenter Roeck <linux@roeck-us.net>
Message-ID: <f05f33ae-d0be-fcf2-0774-c7d0dbda3d36@roeck-us.net>
Date:   Mon, 29 Nov 2021 08:18:34 -0800
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On 11/29/21 8:08 AM, Luca Ceresoli wrote:
> Hi Guenter,
> 
> On 29/11/21 17:04, Guenter Roeck wrote:
>> On Sat, Nov 20, 2021 at 04:57:06PM +0100, Luca Ceresoli wrote:
>>> Clarify why we need to ping the watchdog before changing the timeout by
>>> quoting the MAX77714 datasheet.
>>>
>>
>> Unless I am missing something, this adds confusion instead of clarifying
>> anything, and it is misleading. The added comment in the code makes it
>> sound like clearing the watchdog timer is only needed for MAX77614.
>> However, the code was in place for MAX77620, suggesting that it was needed
>> for that chip as well and is not MAX77614 specific.
> 
> You're right, the comment comes from the max77714-only driver, but now
> that it is in a multi-chip  driver the confusion started to exist.
> 
>> Please either drop this patch or rephrase it to clarify that it applies
>> to both chips.
> 
> What if I rephrase to:
> 
> 	/*
> 	 * "If the value of TWD needs to be changed, clear the system
> 	 * watchdog timer first [...], then change the value of TWD."
> -	 * (MAX77714 datasheet)
> +	 * (MAX77714 datasheet but applies to MAX77620 too)
> 	 */
> 

Sounds good.

Guenter