tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 2a987e65025e2b79c6d453b78cb5985ac6e5eb26 commit: 4434f4c50345c84373b7117b5c827a88870f9d36 pinctrl: bcm2835: Allow building driver as a module date: 6 weeks ago config: mips-randconfig-r001-20211209 (https://download.01.org/0day-ci/archive/20211209/202112091309.HCSKbMQS-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 097a1cb1d5ebb3a0ec4bcaed8ba3ff6a8e33c00a) 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 mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 4434f4c50345c84373b7117b5c827a88870f9d36 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash drivers/pinctrl/bcm/ 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 >>): for (i = 0; i < BCM2835_NUM_IRQS; i++) { ^~~~~~~~~~~~~~~~~~~~ drivers/pinctrl/bcm/pinctrl-bcm2835.c:424:10: note: uninitialized use occurs here switch (group) { ^~~~~ drivers/pinctrl/bcm/pinctrl-bcm2835.c:413:14: note: remove the condition if it is always true for (i = 0; i < BCM2835_NUM_IRQS; i++) { ^~~~~~~~~~~~~~~~~~~~ drivers/pinctrl/bcm/pinctrl-bcm2835.c:410:11: note: initialize the variable 'group' to silence this warning int group; ^ = 0 1 warning generated. vim +413 drivers/pinctrl/bcm/pinctrl-bcm2835.c 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 403 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 404 static void bcm2835_gpio_irq_handler(struct irq_desc *desc) 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 405 { 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 406 struct gpio_chip *chip = irq_desc_get_handler_data(desc); 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 407 struct bcm2835_pinctrl *pc = gpiochip_get_data(chip); 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 408 struct irq_chip *host_chip = irq_desc_get_chip(desc); 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 409 int irq = irq_desc_get_irq(desc); 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 410 int group; 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 411 int i; 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 412 73345a18d464b1 drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2019-08-12 @413 for (i = 0; i < BCM2835_NUM_IRQS; i++) { 73345a18d464b1 drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2019-08-12 414 if (chip->irq.parents[i] == irq) { 0d885e9da176ad drivers/pinctrl/bcm/pinctrl-bcm2835.c Thierry Reding 2017-07-20 415 group = i; 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 416 break; 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 417 } 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 418 } 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 419 /* This should not happen, every IRQ has a bank */ 29d45a642d4ea8 drivers/pinctrl/bcm/pinctrl-bcm2835.c Jason Wang 2021-06-24 420 BUG_ON(i == BCM2835_NUM_IRQS); 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 421 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 422 chained_irq_enter(host_chip, desc); 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 423 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 424 switch (group) { 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 425 case 0: /* IRQ0 covers GPIOs 0-27 */ 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 426 bcm2835_gpio_irq_handle_bank(pc, 0, 0x0fffffff); 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 427 break; 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 428 case 1: /* IRQ1 covers GPIOs 28-45 */ 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 429 bcm2835_gpio_irq_handle_bank(pc, 0, 0xf0000000); 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 430 bcm2835_gpio_irq_handle_bank(pc, 1, 0x00003fff); 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 431 break; b1d84a3d0a26c5 drivers/pinctrl/bcm/pinctrl-bcm2835.c Stefan Wahren 2020-02-08 432 case 2: /* IRQ2 covers GPIOs 46-57 */ 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 433 bcm2835_gpio_irq_handle_bank(pc, 1, 0x003fc000); 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 434 break; 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 435 } 00445b5d5866c7 drivers/pinctrl/bcm/pinctrl-bcm2835.c Phil Elwell 2015-02-24 436 85ae9e512f437c drivers/pinctrl/bcm/pinctrl-bcm2835.c Linus Walleij 2016-11-14 437 chained_irq_exit(host_chip, desc); e1b2dc70cd5b00 drivers/pinctrl/pinctrl-bcm2835.c Simon Arlott 2012-09-27 438 } e1b2dc70cd5b00 drivers/pinctrl/pinctrl-bcm2835.c Simon Arlott 2012-09-27 439 :::::: The code at line 413 was first introduced by commit :::::: 73345a18d464b1b945b29f54f630ace6873344e2 pinctrl: bcm2835: Pass irqchip when adding gpiochip :::::: TO: Linus Walleij <linus.walleij(a)linaro.org&gt; :::::: CC: Linus Walleij <linus.walleij(a)linaro.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org