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, use __maybe_unused to attach this func. 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> --- v2: use __maybe_unused to attach this function, which Guenter suggested. --- drivers/hwmon/pmbus/pmbus_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index 809e666cb52b..e6d3a1118453 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -590,7 +590,7 @@ 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, +static bool __maybe_unused pmbus_check_block_register(struct i2c_client *client, int page, int reg) { int rv; -- 2.17.1