tree: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git testing head: 55ecda6f25ef6de769ae64f162828aee4812c313 commit: 55ecda6f25ef6de769ae64f162828aee4812c313 [12/12] Merge branch 'intel-idle' into linux-next config: x86_64-randconfig-c001 (https://download.01.org/0day-ci/archive/20220428/202204281547.5qD9L1sw-lk...) compiler: gcc-11 (Debian 11.2.0-20) 11.2.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commi... git remote add rafael-pm https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git git fetch --no-tags rafael-pm testing git checkout 55ecda6f25ef6de769ae64f162828aee4812c313 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/idle/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): drivers/idle/intel_idle.c: In function 'adl_idle_state_table_update': drivers/idle/intel_idle.c:1701:17: error: 'disable_promotion_to_c1e' undeclared (first use in this function) 1701 | disable_promotion_to_c1e = true; | ^~~~~~~~~~~~~~~~~~~~~~~~ drivers/idle/intel_idle.c:1701:17: note: each undeclared identifier is reported only once for each function it appears in drivers/idle/intel_idle.c:1706:9: error: implicit declaration of function 'c1e_promotion_enable' [-Werror=implicit-function-declaration] 1706 | c1e_promotion_enable(); | ^~~~~~~~~~~~~~~~~~~~ drivers/idle/intel_idle.c: At top level: 1854 | static void c1e_promotion_enable(void) | ^~~~~~~~~~~~~~~~~~~~ drivers/idle/intel_idle.c:1854:13: error: static declaration of 'c1e_promotion_enable' follows non-static declaration drivers/idle/intel_idle.c:1706:9: note: previous implicit declaration of 'c1e_promotion_enable' with type 'void(void)' 1706 | c1e_promotion_enable(); | ^~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +1854 drivers/idle/intel_idle.c 1aefbd7aeb7695 Rafael J. Wysocki 2020-01-10 1853 da0e58c038e60e Artem Bityutskiy 2022-03-02 @1854 static void c1e_promotion_enable(void) da0e58c038e60e Artem Bityutskiy 2022-03-02 1855 { da0e58c038e60e Artem Bityutskiy 2022-03-02 1856 unsigned long long msr_bits; da0e58c038e60e Artem Bityutskiy 2022-03-02 1857 da0e58c038e60e Artem Bityutskiy 2022-03-02 1858 rdmsrl(MSR_IA32_POWER_CTL, msr_bits); da0e58c038e60e Artem Bityutskiy 2022-03-02 1859 msr_bits |= 0x2; da0e58c038e60e Artem Bityutskiy 2022-03-02 1860 wrmsrl(MSR_IA32_POWER_CTL, msr_bits); da0e58c038e60e Artem Bityutskiy 2022-03-02 1861 } da0e58c038e60e Artem Bityutskiy 2022-03-02 1862 :::::: The code at line 1854 was first introduced by commit :::::: da0e58c038e60e7e65d30813ebdfe91687aa8a24 intel_idle: add 'preferred_cstates' module argument :::::: TO: Artem Bityutskiy <artem.bityutskiy(a)linux.intel.com&gt; :::::: CC: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com&gt; -- 0-DAY CI Kernel Test Service https://01.org/lkp