Hi Min, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 88b06399c9c766c283e070b022b5ceafa4f63f19 commit: e4c6eb68343fb1cfe4bffc6802180e91826f76af ptp: idt82p33: use i2c_master_send for bus write date: 6 months ago config: riscv-randconfig-r022-20210512 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc) 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 riscv cross compiling tool for clang build # apt-get install binutils-riscv64-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 e4c6eb68343fb1cfe4bffc6802180e91826f76af # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv 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 >>): static int idt82p33_probe(struct i2c_client *client, ^ 1 warning generated. vim +/idt82p33_probe +1008 drivers/ptp/ptp_idt82p33.c 57a10d8c112306 Min Li 2020-02-21 1006 57a10d8c112306 Min Li 2020-02-21 1007 57a10d8c112306 Min Li 2020-02-21 @1008 static int idt82p33_probe(struct i2c_client *client, 57a10d8c112306 Min Li 2020-02-21 1009 const struct i2c_device_id *id) 57a10d8c112306 Min Li 2020-02-21 1010 { 57a10d8c112306 Min Li 2020-02-21 1011 struct idt82p33 *idt82p33; 57a10d8c112306 Min Li 2020-02-21 1012 int err; 57a10d8c112306 Min Li 2020-02-21 1013 u8 i; 57a10d8c112306 Min Li 2020-02-21 1014 57a10d8c112306 Min Li 2020-02-21 1015 (void)id; 57a10d8c112306 Min Li 2020-02-21 1016 57a10d8c112306 Min Li 2020-02-21 1017 idt82p33 = devm_kzalloc(&client->dev, 57a10d8c112306 Min Li 2020-02-21 1018 sizeof(struct idt82p33), GFP_KERNEL); 57a10d8c112306 Min Li 2020-02-21 1019 if (!idt82p33) 57a10d8c112306 Min Li 2020-02-21 1020 return -ENOMEM; 57a10d8c112306 Min Li 2020-02-21 1021 57a10d8c112306 Min Li 2020-02-21 1022 mutex_init(&idt82p33->reg_lock); 57a10d8c112306 Min Li 2020-02-21 1023 57a10d8c112306 Min Li 2020-02-21 1024 idt82p33->client = client; 57a10d8c112306 Min Li 2020-02-21 1025 idt82p33->page_offset = 0xff; 57a10d8c112306 Min Li 2020-02-21 1026 idt82p33->tod_write_overhead_ns = 0; 57a10d8c112306 Min Li 2020-02-21 1027 idt82p33->calculate_overhead_flag = 0; 57a10d8c112306 Min Li 2020-02-21 1028 idt82p33->pll_mask = DEFAULT_PLL_MASK; 57a10d8c112306 Min Li 2020-02-21 1029 idt82p33->channel[0].output_mask = DEFAULT_OUTPUT_MASK_PLL0; 57a10d8c112306 Min Li 2020-02-21 1030 idt82p33->channel[1].output_mask = DEFAULT_OUTPUT_MASK_PLL1; 57a10d8c112306 Min Li 2020-02-21 1031 57a10d8c112306 Min Li 2020-02-21 1032 mutex_lock(&idt82p33->reg_lock); 57a10d8c112306 Min Li 2020-02-21 1033 57a10d8c112306 Min Li 2020-02-21 1034 err = idt82p33_load_firmware(idt82p33); 57a10d8c112306 Min Li 2020-02-21 1035 57a10d8c112306 Min Li 2020-02-21 1036 if (err) 57a10d8c112306 Min Li 2020-02-21 1037 dev_warn(&idt82p33->client->dev, 57a10d8c112306 Min Li 2020-02-21 1038 "loading firmware failed with %d\n", err); 57a10d8c112306 Min Li 2020-02-21 1039 57a10d8c112306 Min Li 2020-02-21 1040 if (idt82p33->pll_mask) { 57a10d8c112306 Min Li 2020-02-21 1041 for (i = 0; i < MAX_PHC_PLL; i++) { 57a10d8c112306 Min Li 2020-02-21 1042 if (idt82p33->pll_mask & (1 << i)) { 57a10d8c112306 Min Li 2020-02-21 1043 err = idt82p33_enable_channel(idt82p33, i); e014ae39493f6d Min Li 2020-11-05 1044 if (err) { e014ae39493f6d Min Li 2020-11-05 1045 dev_err(&idt82p33->client->dev, e014ae39493f6d Min Li 2020-11-05 1046 "Failed in %s with err %d!\n", e014ae39493f6d Min Li 2020-11-05 1047 __func__, err); 57a10d8c112306 Min Li 2020-02-21 1048 break; 57a10d8c112306 Min Li 2020-02-21 1049 } 57a10d8c112306 Min Li 2020-02-21 1050 } e014ae39493f6d Min Li 2020-11-05 1051 } 57a10d8c112306 Min Li 2020-02-21 1052 } else { 57a10d8c112306 Min Li 2020-02-21 1053 dev_err(&idt82p33->client->dev, 57a10d8c112306 Min Li 2020-02-21 1054 "no PLLs flagged as PHCs, nothing to do\n"); 57a10d8c112306 Min Li 2020-02-21 1055 err = -ENODEV; 57a10d8c112306 Min Li 2020-02-21 1056 } 57a10d8c112306 Min Li 2020-02-21 1057 57a10d8c112306 Min Li 2020-02-21 1058 mutex_unlock(&idt82p33->reg_lock); 57a10d8c112306 Min Li 2020-02-21 1059 57a10d8c112306 Min Li 2020-02-21 1060 if (err) { 57a10d8c112306 Min Li 2020-02-21 1061 idt82p33_ptp_clock_unregister_all(idt82p33); 57a10d8c112306 Min Li 2020-02-21 1062 return err; 57a10d8c112306 Min Li 2020-02-21 1063 } 57a10d8c112306 Min Li 2020-02-21 1064 57a10d8c112306 Min Li 2020-02-21 1065 i2c_set_clientdata(client, idt82p33); 57a10d8c112306 Min Li 2020-02-21 1066 57a10d8c112306 Min Li 2020-02-21 1067 return 0; 57a10d8c112306 Min Li 2020-02-21 1068 } 57a10d8c112306 Min Li 2020-02-21 1069 :::::: The code at line 1008 was first introduced by commit :::::: 57a10d8c1123068e3cb06434fbc9634f945d3062 ptp: Add a ptp clock driver for IDT 82P33 SMU. :::::: TO: Min Li <min.li.xe(a)renesas.com&gt; :::::: CC: David S. Miller <davem(a)davemloft.net&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org