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Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <593294eb-aecd-2a9c-dc01-1e91b0a00075@roeck-us.net>
Date:   Mon, 8 Aug 2022 14:33:00 -0700
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Subject: Re: [PATCH 2/4] thermal/of: Return -ENODEV instead of -EINVAL if
 registration fails
Content-Language: en-US
To:     Daniel Lezcano <daniel.lezcano@linaro.org>, rafael@kernel.org
Cc:     michael@walle.cc, dan.carpenter@oracle.com,
        linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>
References: <20220808180915.446053-1-daniel.lezcano@linaro.org>
 <20220808180915.446053-2-daniel.lezcano@linaro.org>
 <f8008f05-4e4d-e21f-2e40-e234930ee86e@roeck-us.net>
 <bbd09ad6-db85-5981-a5c1-1dabca1f1b66@linaro.org>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <bbd09ad6-db85-5981-a5c1-1dabca1f1b66@linaro.org>
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On 8/8/22 13:31, Daniel Lezcano wrote:
> On 08/08/2022 20:35, Guenter Roeck wrote:
>> On 8/8/22 11:09, Daniel Lezcano wrote:
>>> The previous version of the OF code was returning -ENODEV if no
>>> thermal zones description was found or if the lookup of the sensor in
>>> the thermal zones was not found.
>>>
>>> The backend drivers are expecting this return value as an information
>>> about skipping the sensor initialization and considered as normal.
>>>
>>> Fix the return value by replacing -EINVAL by -ENODEV
>>>
>>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>>> ---
>>>   drivers/thermal/thermal_of.c | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
>>> index 368eb58e97cf..4210c18ef7b2 100644
>>> --- a/drivers/thermal/thermal_of.c
>>> +++ b/drivers/thermal/thermal_of.c
>>> @@ -329,7 +329,7 @@ static struct device_node *of_thermal_zone_find(struct device_node *sensor, int
>>>       np = of_find_node_by_name(NULL, "thermal-zones");
>>>       if (!np) {
>>>           pr_err("Unable to find thermal zones description\n");
>>
>> I really don't like that error message: People will see it (and complain)
>> whenever a sensor registers and there is no thermal zone, even though that
>> is perfectly normal (see description above).
>>
> 
> I agree, I'll change the message to:
> 
>      pr_info("No thermal zones description\n");
> 
> sounds good ?
> 

I think it should be silent or at best pr_debug.

Guenter

>>> -        return ERR_PTR(-EINVAL);
>>> +        return ERR_PTR(-ENODEV);
>>>       }
>>>       /*
>>> @@ -368,7 +368,7 @@ static struct device_node *of_thermal_zone_find(struct device_node *sensor, int
>>>               }
>>>           }
>>>       }
>>> -    tz = ERR_PTR(-EINVAL);
>>> +    tz = ERR_PTR(-ENODEV);
>>>   out:
>>>       of_node_put(np);
>>>       return tz;
>>
> 
>