Hi Frank, kernel test robot noticed the following build warnings: [auto build test WARNING on tty/tty-testing] [also build test WARNING on tty/tty-next tty/tty-linus robh/for-next linus/master v6.8-rc3 next-20240205] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Frank-Li/i3c-add-target-mode-support/20240203-071519 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing patch link: https://lore.kernel.org/r/20240202230925.1000659-9-Frank.Li%40nxp.com patch subject: [PATCH v6 8/8] tty: i3c: add TTY over I3C master support config: powerpc-randconfig-r071-20240205 (https://download.01.org/0day-ci/archive/20240205/202402052026.UNrmrB2M-lkp@xxxxxxxxx/config) compiler: powerpc-linux-gcc (GCC) 13.2.0 If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202402052026.UNrmrB2M-lkp@xxxxxxxxx/ smatch warnings: drivers/tty/i3c_tty.c:237 tty_i3c_rxwork() error: uninitialized symbol 'status'. vim +/status +237 drivers/tty/i3c_tty.c 191 192 static void tty_i3c_rxwork(struct work_struct *work) 193 { 194 struct ttyi3c_port *sport = container_of(work, struct ttyi3c_port, rxwork); 195 struct i3c_priv_xfer xfers; 196 u32 retry = I3C_TTY_RETRY; 197 u16 status; 198 int ret; 199 200 memset(&xfers, 0, sizeof(xfers)); 201 xfers.data.in = sport->rx_buff; 202 xfers.len = I3C_TTY_TRANS_SIZE; 203 xfers.rnw = 1; 204 205 do { 206 if (test_bit(I3C_TTY_RX_STOP, &sport->status)) 207 break; 208 209 i3c_device_do_priv_xfers(sport->i3cdev, &xfers, 1); 210 211 if (xfers.actual_len) { 212 ret = tty_insert_flip_string(&sport->port, sport->rx_buff, 213 xfers.actual_len); 214 if (ret < xfers.actual_len) 215 sport->buf_overrun++; 216 217 retry = I3C_TTY_RETRY; 218 continue; 219 } 220 221 status = I3C_TTY_TARGET_RX_READY; 222 i3c_device_getstatus_format1(sport->i3cdev, &status); 223 /* 224 * Target side needs some time to fill data into fifo. Target side may not 225 * have hardware update status in real time. Software update status always 226 * needs some delays. 227 * 228 * Generally, target side have circular buffer in memory, it will be moved 229 * into FIFO by CPU or DMA. 'status' just show if circular buffer empty. But 230 * there are gap, especially CPU have not response irq to fill FIFO in time. 231 * So xfers.actual will be zero, wait for little time to avoid flood 232 * transfer in i3c bus. 233 */ 234 usleep_range(I3C_TTY_YIELD_US, 10 * I3C_TTY_YIELD_US); 235 retry--; 236 > 237 } while (retry && (status & I3C_TTY_TARGET_RX_READY)); 238 239 tty_flip_buffer_push(&sport->port); 240 } 241 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki