Hi Biwen, Thank you for the patch! Yet something to improve: [auto build test ERROR on v5.9] [cannot apply to wsa/i2c/for-next next-20201016] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Biwen-Li/i2c-imx-support-slave-m... base: bbf5c979011a099af5dc76498918ed7df445635b config: arm-randconfig-r004-20201019 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 094e9f4779eb9b5c6a49014f2f80b8cbb833572f) 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 arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://github.com/0day-ci/linux/commit/afe1305a21d6e88b2c015cf62f84893cd... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Biwen-Li/i2c-imx-support-slave-mode-for-imx-I2C-driver/20201016-163639 git checkout afe1305a21d6e88b2c015cf62f84893cd9c462d5 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_REQUESTED, &value); ^ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_REQUESTED, &value); ^ drivers/i2c/busses/i2c-imx.c:677:4: error: implicit declaration of function 'i2c_slave_event' [-Werror,-Wimplicit-function-declaration] i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_REQUESTED, &value); ^ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_REQUESTED, &value); ^ drivers/i2c/busses/i2c-imx.c:688:4: error: implicit declaration of function 'i2c_slave_event' [-Werror,-Wimplicit-function-declaration] i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_RECEIVED, &value); ^ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_WRITE_RECEIVED, &value); ^ drivers/i2c/busses/i2c-imx.c:692:4: error: implicit declaration of function 'i2c_slave_event' [-Werror,-Wimplicit-function-declaration] i2c_slave_event(i2c_imx->slave, I2C_SLAVE_STOP, &value); ^ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_STOP, &value); ^ drivers/i2c/busses/i2c-imx.c:698:3: error: implicit declaration of function 'i2c_slave_event' [-Werror,-Wimplicit-function-declaration] i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_PROCESSED, &value); ^ i2c_slave_event(i2c_imx->slave, I2C_SLAVE_READ_PROCESSED, &value); ^ .reg_slave = i2c_imx_reg_slave, ^ .unreg_slave = i2c_imx_unreg_slave, ^ 12 errors generated. vim +/i2c_slave_event +667 drivers/i2c/busses/i2c-imx.c 656 657 static irqreturn_t i2c_imx_slave_isr(struct imx_i2c_struct *i2c_imx, 658 unsigned int status, unsigned int ctl) 659 { 660 u8 value; 661 662 if (status & I2SR_IAL) { /* Arbitration lost */ 663 i2c_imx_clr_al_bit(status | I2SR_IIF, i2c_imx); 664 } else if (status & I2SR_IAAS) { /* Addressed as a slave */ 665 if (status & I2SR_SRW) { /* Master wants to read from us*/ 666 dev_dbg(&i2c_imx->adapter.dev, "read requested"); 668 669 /* Slave transmit */ 670 ctl |= I2CR_MTX; 671 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 672 673 /* Send data */ 674 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); 675 } else { /* Master wants to write to us */ 676 dev_dbg(&i2c_imx->adapter.dev, "write requested"); 678 679 /* Slave receive */ 680 ctl &= ~I2CR_MTX; 681 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 682 /* Dummy read */ 683 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 684 } 685 } else if (!(ctl & I2CR_MTX)) { /* Receive mode */ 686 if (status & I2SR_IBB) { /* No STOP signal detected */ 687 value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 689 } else { /* STOP signal is detected */ 690 dev_dbg(&i2c_imx->adapter.dev, 691 "STOP signal detected"); 693 } 694 } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */ 695 ctl |= I2CR_MTX; 696 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 697 699 700 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); 701 } else { /* Transmit mode received NAK */ 702 ctl &= ~I2CR_MTX; 703 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 704 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 705 } 706 707 return IRQ_HANDLED; 708 } 709 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org