tree: https://chromium.googlesource.com/chromiumos/third_party/kernel chromeos-4.4 head: ca018b971e8a0de8ddb9f24e14d458b679bdd135 commit: ca018b971e8a0de8ddb9f24e14d458b679bdd135 [13/13] BACKPORT: spi: Add driver_override SPI device attribute config: arc-allyesconfig (attached as .config) compiler: arceb-elf-gcc (GCC) 9.3.0 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 git remote add chrome-os https://chromium.googlesource.com/chromiumos/third_party/kernel git fetch --no-tags chrome-os chromeos-4.4 git checkout ca018b971e8a0de8ddb9f24e14d458b679bdd135 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc 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 >>): In file included from arch/arc/include/asm/bug.h:32, from include/linux/bug.h:4, from include/linux/debug_locks.h:6, from include/linux/lockdep.h:23, from include/linux/spinlock_types.h:18, from include/linux/mutex.h:15, from include/linux/kernfs.h:13, from include/linux/sysfs.h:15, from include/linux/kobject.h:21, from include/linux/device.h:17, from drivers/spi/spi.c:19: include/linux/cpumask.h: In function 'cpumask_check': include/linux/cpumask.h:117:19: warning: comparison of integer expressions of different signedness: 'unsigned int' and 'int' [-Wsign-compare] 117 | WARN_ON_ONCE(cpu >= nr_cpumask_bits); | ^~ include/asm-generic/bug.h:123:27: note: in definition of macro 'WARN_ON_ONCE' 123 | int __ret_warn_once = !!(condition); \ | ^~~~~~~~~ drivers/spi/spi.c: In function 'driver_override_store': 77 | const size_t len = end ? end - buf : count; | ^~~~~~~~~ drivers/spi/spi.c: In function 'spi_register_board_info': drivers/spi/spi.c:718:16: warning: comparison of integer expressions of different signedness: 'int' and 'unsigned int' [-Wsign-compare] 718 | for (i = 0; i < n; i++, bi++, info++) { | ^ drivers/spi/spi.c: In function 'spi_write_then_read': drivers/spi/spi.c:2774:20: warning: comparison of integer expressions of different signedness: 'unsigned int' and 'int' [-Wsign-compare] 2774 | if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { | ^ In file included from include/linux/perf_event.h:24, from include/linux/trace_events.h:9, from include/trace/trace_events.h:19, from include/trace/define_trace.h:90, from include/trace/events/spi.h:156, from drivers/spi/spi.c:42: At top level: arch/arc/include/asm/perf_event.h:127:23: warning: 'arc_pmu_cache_map' defined but not used [-Wunused-const-variable=] 127 | static const unsigned arc_pmu_cache_map[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = { | ^~~~~~~~~~~~~~~~~ arch/arc/include/asm/perf_event.h:95:27: warning: 'arc_pmu_ev_hw_map' defined but not used [-Wunused-const-variable=] 95 | static const char * const arc_pmu_ev_hw_map[] = { | ^~~~~~~~~~~~~~~~~ vim +77 drivers/spi/spi.c 70 71 static ssize_t driver_override_store(struct device *dev, 72 struct device_attribute *a, 73 const char *buf, size_t count) 74 { 75 struct spi_device *spi = to_spi_device(dev); 76 const char *end = memchr(buf, '\n', count); 78 const char *driver_override, *old; 79 80 /* We need to keep extra room for a newline when displaying value */ 81 if (len >= (PAGE_SIZE - 1)) 82 return -EINVAL; 83 84 driver_override = kstrndup(buf, len, GFP_KERNEL); 85 if (!driver_override) 86 return -ENOMEM; 87 88 device_lock(dev); 89 old = spi->driver_override; 90 if (len) { 91 spi->driver_override = driver_override; 92 } else { 93 /* Emptry string, disable driver override */ 94 spi->driver_override = NULL; 95 kfree(driver_override); 96 } 97 device_unlock(dev); 98 kfree(old); 99 100 return count; 101 } 102 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org