Hi Tetsuo, I love your patch! Perhaps something to improve: [auto build test WARNING on next-20200519] [cannot apply to linus/master linux/master pmladek/for-next v5.7-rc6 v5.7-rc5 v5.7-rc4 v5.7-rc7] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Tetsuo-Handa/twist-allow-converting-pr_devel-pr_debug-into-printk-KERN_DEBUG/20200524-225318 base: fb57b1fabcb28f358901b2df90abd2b48abc1ca8 config: powerpc-allmodconfig (attached as .config) compiler: powerpc64-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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot All warnings (new ones prefixed by >>, old ones prefixed by <<): In file included from include/linux/device.h:15, from include/linux/acpi.h:15, from include/linux/i2c.h:13, from drivers/iio/adc/ina2xx-adc.c:24: drivers/iio/adc/ina2xx-adc.c: In function 'ina2xx_buffer_enable': include/linux/dev_printk.h:115:2: error: implicit declaration of function 'dynamic_dev_dbg' [-Werror=implicit-function-declaration] 115 | dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__) | ^~~~~~~~~~~~~~~ >> drivers/iio/adc/ina2xx-adc.c:834:2: note: in expansion of macro 'dev_dbg' 834 | dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%un", | ^~~~~~~ cc1: some warnings being treated as errors vim +/dev_dbg +834 drivers/iio/adc/ina2xx-adc.c c43a102e67db99c Marc Titinger 2015-12-07 827 c43a102e67db99c Marc Titinger 2015-12-07 828 static int ina2xx_buffer_enable(struct iio_dev *indio_dev) c43a102e67db99c Marc Titinger 2015-12-07 829 { c43a102e67db99c Marc Titinger 2015-12-07 830 struct ina2xx_chip_info *chip = iio_priv(indio_dev); c43a102e67db99c Marc Titinger 2015-12-07 831 unsigned int sampling_us = SAMPLING_PERIOD(chip); 7d6cd21d82bacab Akinobu Mita 2018-06-25 832 struct task_struct *task; c43a102e67db99c Marc Titinger 2015-12-07 833 1961bce76452938 Andrew F. Davis 2016-02-24 @834 dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n", c43a102e67db99c Marc Titinger 2015-12-07 835 (unsigned int)(*indio_dev->active_scan_mask), c43a102e67db99c Marc Titinger 2015-12-07 836 1000000 / sampling_us, chip->avg); c43a102e67db99c Marc Titinger 2015-12-07 837 1961bce76452938 Andrew F. Davis 2016-02-24 838 dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us); 1961bce76452938 Andrew F. Davis 2016-02-24 839 dev_dbg(&indio_dev->dev, "Async readout mode: %d\n", 1961bce76452938 Andrew F. Davis 2016-02-24 840 chip->allow_async_readout); c43a102e67db99c Marc Titinger 2015-12-07 841 7d6cd21d82bacab Akinobu Mita 2018-06-25 842 task = kthread_create(ina2xx_capture_thread, (void *)indio_dev, 46294cd948d530d Marc Titinger 2015-12-11 843 "%s:%d-%uus", indio_dev->name, indio_dev->id, 46294cd948d530d Marc Titinger 2015-12-11 844 sampling_us); 7d6cd21d82bacab Akinobu Mita 2018-06-25 845 if (IS_ERR(task)) 7d6cd21d82bacab Akinobu Mita 2018-06-25 846 return PTR_ERR(task); 7d6cd21d82bacab Akinobu Mita 2018-06-25 847 7d6cd21d82bacab Akinobu Mita 2018-06-25 848 get_task_struct(task); 7d6cd21d82bacab Akinobu Mita 2018-06-25 849 wake_up_process(task); 7d6cd21d82bacab Akinobu Mita 2018-06-25 850 chip->task = task; c43a102e67db99c Marc Titinger 2015-12-07 851 7d6cd21d82bacab Akinobu Mita 2018-06-25 852 return 0; c43a102e67db99c Marc Titinger 2015-12-07 853 } c43a102e67db99c Marc Titinger 2015-12-07 854 :::::: The code at line 834 was first introduced by commit :::::: 1961bce76452938eed8f797b7d96ab5f3c611525 iio: ina2xx: Remove trace_printk debug statments :::::: TO: Andrew F. Davis :::::: CC: Jonathan Cameron --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org