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Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <f8008f05-4e4d-e21f-2e40-e234930ee86e@roeck-us.net>
Date:   Mon, 8 Aug 2022 11:35:34 -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>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <20220808180915.446053-2-daniel.lezcano@linaro.org>
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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).

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;