Re: [PATCH -next] hwmon: (pmbus) fix build error unused-function

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 6/8/22 01:49, Ren Zhijie wrote:
> If CONFIG_PMBUS is y and CONFIG_DEBUG_FS is not set.
>
> make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-, will be failed, like this:
> drivers/hwmon/pmbus/pmbus_core.c:593:13: error: ‘pmbus_check_block_register’ defined but not used [-Werror=unused-function]
>   static bool pmbus_check_block_register(struct i2c_client *client, int page,
>               ^~~~~~~~~~~~~~~~~~~~~~~~~~
> cc1: all warnings being treated as errors
> make[3]: *** [drivers/hwmon/pmbus/pmbus_core.o] Error 1
> make[2]: *** [drivers/hwmon/pmbus] Error 2
> make[2]: *** Waiting for unfinished jobs....
> make[1]: *** [drivers/hwmon] Error 2
> make[1]: *** Waiting for unfinished jobs....
> make: *** [drivers] Error 2
>
> To fix building warning, wrap all related code with CONFIG_DEBUG_F.

Please use __maybe_unused for the affected functions instead.

Thanks,
Guenter

> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Fixes: c3ffc3a1ff83("hwmon: (pmbus) add a function to check the presence of a block register")
> Signed-off-by: Ren Zhijie <renzhijie2@xxxxxxxxxx>
> ---
>   drivers/hwmon/pmbus/pmbus_core.c | 56 ++++++++++++++++----------------
>   1 file changed, 28 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 809e666cb52b..2c68ab1fe697 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -441,18 +441,6 @@ int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
>   }
>   EXPORT_SYMBOL_NS_GPL(pmbus_update_byte_data, PMBUS);
>   
> -static int pmbus_read_block_data(struct i2c_client *client, int page, u8 reg,
> -				 char *data_buf)
> -{
> -	int rv;
> -
> -	rv = pmbus_set_page(client, page, 0xff);
> -	if (rv < 0)
> -		return rv;
> -
> -	return i2c_smbus_read_block_data(client, reg, data_buf);
> -}
> -
>   static struct pmbus_sensor *pmbus_find_sensor(struct pmbus_data *data, int page,
>   					      int reg)
>   {
> @@ -590,22 +578,6 @@ bool pmbus_check_word_register(struct i2c_client *client, int page, int reg)
>   }
>   EXPORT_SYMBOL_NS_GPL(pmbus_check_word_register, PMBUS);
>   
> -static bool pmbus_check_block_register(struct i2c_client *client, int page,
> -				       int reg)
> -{
> -	int rv;
> -	struct pmbus_data *data = i2c_get_clientdata(client);
> -	char data_buf[I2C_SMBUS_BLOCK_MAX + 2];
> -
> -	rv = pmbus_read_block_data(client, page, reg, data_buf);
> -	if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
> -		rv = pmbus_check_status_cml(client);
> -	if (rv < 0 && (data->flags & PMBUS_READ_STATUS_AFTER_FAILED_CHECK))
> -		data->read_status(client, -1);
> -	pmbus_clear_fault_page(client, -1);
> -	return rv >= 0;
> -}
> -
>   const struct pmbus_driver_info *pmbus_get_driver_info(struct i2c_client *client)
>   {
>   	struct pmbus_data *data = i2c_get_clientdata(client);
> @@ -2961,6 +2933,34 @@ static int pmbus_regulator_register(struct pmbus_data *data)
>   static struct dentry *pmbus_debugfs_dir;	/* pmbus debugfs directory */
>   
>   #if IS_ENABLED(CONFIG_DEBUG_FS)
> +static int pmbus_read_block_data(struct i2c_client *client, int page, u8 reg,
> +				 char *data_buf)
> +{
> +	int rv;
> +
> +	rv = pmbus_set_page(client, page, 0xff);
> +	if (rv < 0)
> +		return rv;
> +
> +	return i2c_smbus_read_block_data(client, reg, data_buf);
> +}
> +
> +static bool pmbus_check_block_register(struct i2c_client *client, int page,
> +				       int reg)
> +{
> +	int rv;
> +	struct pmbus_data *data = i2c_get_clientdata(client);
> +	char data_buf[I2C_SMBUS_BLOCK_MAX + 2];
> +
> +	rv = pmbus_read_block_data(client, page, reg, data_buf);
> +	if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
> +		rv = pmbus_check_status_cml(client);
> +	if (rv < 0 && (data->flags & PMBUS_READ_STATUS_AFTER_FAILED_CHECK))
> +		data->read_status(client, -1);
> +	pmbus_clear_fault_page(client, -1);
> +	return rv >= 0;
> +}
> +
>   static int pmbus_debugfs_get(void *data, u64 *val)
>   {
>   	int rc;