tree: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git bleeding-edge head: 506a524e05e240d2878cf86a56c47e72e09d329f commit: bc5706eaeae0b51385d3859b0fdf17a2c8fdc134 [46/47] ACPI: processor: Fix CPU0 wakeup in acpi_idle_play_dead() config: x86_64-randconfig-s022-20210330 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-279-g6d5d9b42-dirty # https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commi... git remote add pm https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git git fetch --no-tags pm bleeding-edge git checkout bc5706eaeae0b51385d3859b0fdf17a2c8fdc134 # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64 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/acpi/processor_idle.c: In function 'acpi_idle_play_dead': 546 | #ifdef defined(CONFIG_X86) && defined(CONFIG_HOTPLUG_CPU) | ^ drivers/acpi/processor_idle.c: At top level: drivers/acpi/processor_idle.c:1103:12: warning: no previous prototype for 'acpi_processor_ffh_lpi_probe' [-Wmissing-prototypes] 1103 | int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/acpi/processor_idle.c:1108:12: warning: no previous prototype for 'acpi_processor_ffh_lpi_enter' [-Wmissing-prototypes] 1108 | int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for ADI_AXI_ADC Depends on IIO && HAS_IOMEM && OF Selected by - AD9467 && IIO && SPI vim +546 drivers/acpi/processor_idle.c 524 525 /** 526 * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining) 527 * @dev: the target CPU 528 * @index: the index of suggested state 529 */ 530 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) 531 { 532 struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); 533 534 ACPI_FLUSH_CPU_CACHE(); 535 536 while (1) { 537 538 if (cx->entry_method == ACPI_CSTATE_HALT) 539 safe_halt(); 540 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) { 541 inb(cx->address); 542 wait_for_freeze(); 543 } else 544 return -ENODEV; 545 547 /* If NMI wants to wake up CPU0, start CPU0. */ 548 if (wakeup_cpu0()) 549 start_cpu0(); 550 #endif 551 } 552 553 /* Never reached */ 554 return 0; 555 } 556 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org