Hi Krzysztof, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 009c9aa5be652675a06d5211e1640e02bbb1c33d commit: 4a2d5f663dab6614772d8e28ca190b127ba46d9d i2c: Enable compile testing for more drivers date: 1 year, 5 months ago config: parisc-randconfig-r023-20210615 (attached as .config) compiler: hppa-linux-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 # 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 4a2d5f663dab6614772d8e28ca190b127ba46d9d # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc 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/parisc/include/asm/io.h:6, from include/linux/io.h:13, from drivers/i2c/busses/i2c-mlxcpld.c:37: include/asm-generic/pgtable.h: In function 'pte_clear_not_present_full': arch/parisc/include/asm/pgtable.h:96:9: warning: variable 'old_pte' set but not used [-Wunused-but-set-variable] 96 | pte_t old_pte; \ | ^~~~~~~ arch/parisc/include/asm/pgtable.h:322:34: note: in expansion of macro 'set_pte_at' 322 | #define pte_clear(mm, addr, xp) set_pte_at(mm, addr, xp, __pte(0)) | ^~~~~~~~~~ include/asm-generic/pgtable.h:201:2: note: in expansion of macro 'pte_clear' 201 | pte_clear(mm, address, ptep); | ^~~~~~~~~ include/asm-generic/pgtable.h: In function '__ptep_modify_prot_commit': arch/parisc/include/asm/pgtable.h:96:9: warning: variable 'old_pte' set but not used [-Wunused-but-set-variable] 96 | pte_t old_pte; \ | ^~~~~~~ include/asm-generic/pgtable.h:640:2: note: in expansion of macro 'set_pte_at' 640 | set_pte_at(vma->vm_mm, addr, ptep, pte); | ^~~~~~~~~~ drivers/i2c/busses/i2c-mlxcpld.c: In function 'mlxcpld_i2c_check_busy': 271 | if (val & MLXCPLD_LPCI2C_TRANS_END) | ^ vim +/val +271 drivers/i2c/busses/i2c-mlxcpld.c 6bec23bff91491 Vadim Pasternak 2016-11-20 263 6bec23bff91491 Vadim Pasternak 2016-11-20 264 /* Make sure the CPLD is ready to start transmitting. */ 6bec23bff91491 Vadim Pasternak 2016-11-20 265 static int mlxcpld_i2c_check_busy(struct mlxcpld_i2c_priv *priv) 6bec23bff91491 Vadim Pasternak 2016-11-20 266 { 6bec23bff91491 Vadim Pasternak 2016-11-20 267 u8 val; 6bec23bff91491 Vadim Pasternak 2016-11-20 268 6bec23bff91491 Vadim Pasternak 2016-11-20 269 mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_STATUS_REG, &val, 1); 6bec23bff91491 Vadim Pasternak 2016-11-20 270 6bec23bff91491 Vadim Pasternak 2016-11-20 @271 if (val & MLXCPLD_LPCI2C_TRANS_END) 6bec23bff91491 Vadim Pasternak 2016-11-20 272 return 0; 6bec23bff91491 Vadim Pasternak 2016-11-20 273 6bec23bff91491 Vadim Pasternak 2016-11-20 274 return -EIO; 6bec23bff91491 Vadim Pasternak 2016-11-20 275 } 6bec23bff91491 Vadim Pasternak 2016-11-20 276 :::::: The code at line 271 was first introduced by commit :::::: 6bec23bff914915822f2c34d0555902fb2b9be1f i2c: mlxcpld: add master driver for mellanox systems :::::: TO: Vadim Pasternak <vadimp(a)mellanox.com&gt; :::::: CC: Wolfram Sang <wsa(a)the-dreams.de&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org