tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 4333a9b0b67bb4e8bcd91bdd80da80b0ec151162 commit: 48ba02b2e2b1a1c80718e93fefe99c8319597c4a usb: gadget: add udc driver for max3420 date: 3 months ago config: x86_64-randconfig-a014-20200620 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project f5bbe390d23d7da0ffb110cdb24b583c2dc87eba) 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 git checkout 48ba02b2e2b1a1c80718e93fefe99c8319597c4a # 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: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): static int max3420_thread(void *dev_id) ^ 1 warning generated. vim +/max3420_thread +844 drivers/usb/gadget/udc/max3420_udc.c 843 845 { 846 struct max3420_udc *udc = dev_id; 847 struct spi_device *spi = udc->spi; 848 int i, loop_again = 1; 849 unsigned long flags; 850 851 while (!kthread_should_stop()) { 852 if (!loop_again) { 853 ktime_t kt = ns_to_ktime(1000 * 1000 * 250); /* 250ms */ 854 855 set_current_state(TASK_INTERRUPTIBLE); 856 857 spin_lock_irqsave(&udc->lock, flags); 858 if (udc->todo & ENABLE_IRQ) { 859 enable_irq(spi->irq); 860 udc->todo &= ~ENABLE_IRQ; 861 } 862 spin_unlock_irqrestore(&udc->lock, flags); 863 864 schedule_hrtimeout(&kt, HRTIMER_MODE_REL); 865 } 866 loop_again = 0; 867 868 mutex_lock(&udc->spi_bus_mutex); 869 870 /* If bus-vbus_active and disconnected */ 871 if (!udc->vbus_active || !udc->softconnect) 872 goto loop; 873 874 if (max3420_start(udc)) { 875 loop_again = 1; 876 goto loop; 877 } 878 879 if (max3420_handle_irqs(udc)) { 880 loop_again = 1; 881 goto loop; 882 } 883 884 if (spi_max3420_rwkup(udc)) { 885 loop_again = 1; 886 goto loop; 887 } 888 889 max3420_do_data(udc, 0, 1); /* get done with the EP0 ZLP */ 890 891 for (i = 1; i < MAX3420_MAX_EPS; i++) { 892 struct max3420_ep *ep = &udc->ep[i]; 893 894 if (spi_max3420_enable(ep)) 895 loop_again = 1; 896 if (spi_max3420_stall(ep)) 897 loop_again = 1; 898 } 899 loop: 900 mutex_unlock(&udc->spi_bus_mutex); 901 } 902 903 set_current_state(TASK_RUNNING); 904 dev_info(udc->dev, "SPI thread exiting"); 905 return 0; 906 } 907 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org