Hi Xianting, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tty/tty-testing] [also build test WARNING on char-misc/char-misc-testing soc/for-next v5.14-rc5 next-20210812] [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/Xianting-Tian/make-hvc-pass-dma-... base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing config: hexagon-randconfig-r041-20210812 (attached as .config) compiler: clang version 12.0.0 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://github.com/0day-ci/linux/commit/9f2925b5429149ceb0ea6eeaa8c81d422... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Xianting-Tian/make-hvc-pass-dma-capable-memory-to-its-backend/20210812-174847 git checkout 9f2925b5429149ceb0ea6eeaa8c81d422c3124fc # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon 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 >>): spin_unlock_irqrestore(&hp->c_lock, flags); ^~ drivers/tty/hvc/hvc_console.c:149:23: note: initialize the variable 'hp' to silence this warning struct hvc_struct *hp; ^ = NULL 1 warning generated. vim +/hp +190 drivers/tty/hvc/hvc_console.c 136 137 /* 138 * Console APIs, NOT TTY. These APIs are available immediately when 139 * hvc_console_setup() finds adapters. 140 */ 141 142 static void hvc_console_print(struct console *co, const char *b, 143 unsigned count) 144 { 145 char *c; 146 unsigned i = 0, n = 0; 147 int r, donecr = 0, index = co->index; 148 unsigned long flags; 149 struct hvc_struct *hp; 150 151 /* Console access attempt outside of acceptable console range. */ 152 if (index >= MAX_NR_HVC_CONSOLES) 153 return; 154 155 /* This console adapter was removed so it is not usable. */ 156 if (vtermnos[index] == -1 || !cons_outbuf[index]) 157 return; 158 159 c = cons_outbuf[index]; 160 161 spin_lock_irqsave(&hp->c_lock, flags); 162 while (count > 0 || i > 0) { 163 if (count > 0 && i < sizeof(c)) { 164 if (b[n] == '\n' && !donecr) { 165 c[i++] = '\r'; 166 donecr = 1; 167 } else { 168 c[i++] = b[n++]; 169 donecr = 0; 170 --count; 171 } 172 } else { 173 r = cons_ops[index]->put_chars(vtermnos[index], c, i); 174 if (r <= 0) { 175 /* throw away characters on error 176 * but spin in case of -EAGAIN */ 177 if (r != -EAGAIN) { 178 i = 0; 179 } else { 180 hvc_console_flush(cons_ops[index], 181 vtermnos[index]); 182 } 183 } else if (r > 0) { 184 i -= r; 185 if (i > 0) 186 memmove(c, c+r, i); 187 } 188 } 189 } 191 hvc_console_flush(cons_ops[index], vtermnos[index]); 192 } 193 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org