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: h8300-randconfig-r021-20210212 (attached as .config) compiler: h8300-linux-gcc (GCC) 7.5.0 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-7.5.0 make.cross ARCH=h8300 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/spi/spi.c: In function 'driver_override_store': 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 between signed and unsigned integer expressions [-Wsign-compare] 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 between signed and unsigned integer expressions [-Wsign-compare] if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { ^ 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