Hi Jean-Jacques, FYI, the error/warning still remains. tree: git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git ti-rt-linux-5.4.y head: 872a510b1bbcab3969980f7fdaa664d7818c0210 commit: ced430ccdcbc2a14c064ec67d722daec9680e809 [136/9607] backlight: led_bl: Add support for a "enable" gpio config: sparc64-randconfig-r033-20200818 (attached as .config) compiler: sparc64-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout ced430ccdcbc2a14c064ec67d722daec9680e809 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=sparc64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/video/backlight/led_bl.c: In function 'led_bl_set_brightness': 40 | gpiod_set_value_cansleep(priv->enable_gpio, 1); | ^~~~~~~~~~~~~~~~~~~~~~~~ | gpio_set_value_cansleep drivers/video/backlight/led_bl.c: In function 'led_bl_probe': 242 | priv->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", | ^~~~~~~~~~~~~~~~~~~~~~~ 243 | GPIOD_OUT_LOW); | ^~~~~~~~~~~~~ | GPIOF_INIT_LOW drivers/video/backlight/led_bl.c:243:11: note: each undeclared identifier is reported only once for each function it appears in cc1: some warnings being treated as errors git remote add ti git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git git fetch --no-tags ti ti-rt-linux-5.4.y git checkout ced430ccdcbc2a14c064ec67d722daec9680e809 vim +40 drivers/video/backlight/led_bl.c 25 26 static void led_bl_set_brightness(struct led_bl_data *priv, int level) 27 { 28 int i; 29 int bkl_brightness; 30 31 if (priv->levels) 32 bkl_brightness = priv->levels[level]; 33 else 34 bkl_brightness = level; 35 36 for (i = 0; i < priv->nb_leds; i++) 37 led_set_brightness(priv->leds[i], bkl_brightness); 38 39 if (!priv->enabled) 41 42 priv->enabled = true; 43 } 44 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org