Re: [PATCH 1/2] hwmon: gpio-fan: mark OF related data as maybe unused

From: Guenter Roeck <linux@roeck-us.net>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Jean Delvare <jdelvare@suse.com>,
	Eric Tremblay <etremblay@distech-controls.com>,
	linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] hwmon: gpio-fan: mark OF related data as maybe unused
Date: Sun, 12 Mar 2023 11:06:55 -0700	[thread overview]
Message-ID: <cd9067c7-0b99-4d62-9d5a-cdc028f33ba5@roeck-us.net> (raw)
In-Reply-To: <20230311111610.251774-1-krzysztof.kozlowski@linaro.org>

On Sat, Mar 11, 2023 at 12:16:09PM +0100, Krzysztof Kozlowski wrote:
> The driver can be compile tested with !CONFIG_OF making certain data
> unused:
> 
>   drivers/hwmon/gpio-fan.c:484:34: error: ‘of_gpio_fan_match’ defined but not used [-Werror=unused-const-variable=]
> 

How do you trigger that ? The driver depends on OF_GPIO which
in turn depends on OF. Arguably that means that of_match_ptr()
doesnot really make sense, but still I don't see how you can
trigger the above error message.

Thanks,
Guenter

> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
>  drivers/hwmon/gpio-fan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
> index e75db6f64e8c..be7f06fb7f78 100644
> --- a/drivers/hwmon/gpio-fan.c
> +++ b/drivers/hwmon/gpio-fan.c
> @@ -481,7 +481,7 @@ static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
>  	return 0;
>  }
>  
> -static const struct of_device_id of_gpio_fan_match[] = {
> +static const struct of_device_id of_gpio_fan_match[] __maybe_unused = {
>  	{ .compatible = "gpio-fan", },
>  	{},
>  };