Hi Kuninori, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on asoc/for-next] [also build test WARNING on next-20200519] [cannot apply to sound/for-next v5.7-rc6] [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/Kuninori-Morimoto/ASoC-add-soc-l... base: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next config: x86_64-randconfig-r016-20200521 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 3393cc4cebf9969db94dc424b7a2b6195589c33b) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): sound/soc/soc-link.c:28:5: warning: no previous prototype for function 'snd_soc_link_init' [-Wmissing-prototypes] int snd_soc_link_init(struct snd_soc_pcm_runtime *rtd) ^ sound/soc/soc-link.c:28:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int snd_soc_link_init(struct snd_soc_pcm_runtime *rtd) ^ static int snd_soc_link_startup(struct snd_soc_pcm_runtime *rtd, ^ sound/soc/soc-link.c:38:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int snd_soc_link_startup(struct snd_soc_pcm_runtime *rtd, ^ static void snd_soc_link_shutdown(struct snd_soc_pcm_runtime *rtd, ^ sound/soc/soc-link.c:50:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void snd_soc_link_shutdown(struct snd_soc_pcm_runtime *rtd, ^ static int snd_soc_link_prepare(struct snd_soc_pcm_runtime *rtd, ^ sound/soc/soc-link.c:58:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int snd_soc_link_prepare(struct snd_soc_pcm_runtime *rtd, ^ static int snd_soc_link_hw_params(struct snd_soc_pcm_runtime *rtd, ^ sound/soc/soc-link.c:70:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int snd_soc_link_hw_params(struct snd_soc_pcm_runtime *rtd, ^ static void snd_soc_link_hw_free(struct snd_soc_pcm_runtime *rtd, ^ sound/soc/soc-link.c:83:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void snd_soc_link_hw_free(struct snd_soc_pcm_runtime *rtd, ^ static int snd_soc_link_trigger(struct snd_soc_pcm_runtime *rtd, ^ sound/soc/soc-link.c:91:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int snd_soc_link_trigger(struct snd_soc_pcm_runtime *rtd, ^ static 7 warnings generated. vim +/snd_soc_link_startup +38 sound/soc/soc-link.c 37 39 struct snd_pcm_substream *substream) 40 { 41 int ret = 0; 42 43 if (rtd->dai_link->ops && 44 rtd->dai_link->ops->startup) 45 ret = rtd->dai_link->ops->startup(substream); 46 47 return soc_link_ret(rtd, ret); 48 } 49 51 struct snd_pcm_substream *substream) 52 { 53 if (rtd->dai_link->ops && 54 rtd->dai_link->ops->shutdown) 55 rtd->dai_link->ops->shutdown(substream); 56 } 57 59 struct snd_pcm_substream *substream) 60 { 61 int ret = 0; 62 63 if (rtd->dai_link->ops && 64 rtd->dai_link->ops->prepare) 65 ret = rtd->dai_link->ops->prepare(substream); 66 67 return soc_link_ret(rtd, ret); 68 } 69 71 struct snd_pcm_substream *substream, 72 struct snd_pcm_hw_params *params) 73 { 74 int ret = 0; 75 76 if (rtd->dai_link->ops && 77 rtd->dai_link->ops->hw_params) 78 ret = rtd->dai_link->ops->hw_params(substream, params); 79 80 return soc_link_ret(rtd, ret); 81 } 82 84 struct snd_pcm_substream *substream) 85 { 86 if (rtd->dai_link->ops && 87 rtd->dai_link->ops->hw_free) 88 rtd->dai_link->ops->hw_free(substream); 89 } 90 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org