Hi Starke", Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tty/tty-testing] [also build test WARNING on linus/master v6.0-rc2 next-20220822] [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/D-Starke/tty-n_gsm-add-enumeration-for-gsm-encodings/20220822-152532 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing config: i386-randconfig-a003-20220822 (https://download.01.org/0day-ci/archive/20220822/202208222147.WfFRmf1r-lkp@xxxxxxxxx/config) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1) 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/intel-lab-lkp/linux/commit/66ec0ad14dba76f793ec89ecdc7e6d7b3c550873 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review D-Starke/tty-n_gsm-add-enumeration-for-gsm-encodings/20220822-152532 git checkout 66ec0ad14dba76f793ec89ecdc7e6d7b3c550873 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/tty/ If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> drivers/tty/n_gsm.c:1928:34: warning: variable 'len' is uninitialized when used here [-Wuninitialized] pr_debug("%d bytes for tty\n", len); ^~~ include/linux/printk.h:588:26: note: expanded from macro 'pr_debug' dynamic_pr_debug(fmt, ##__VA_ARGS__) ^~~~~~~~~~~ include/linux/dynamic_debug.h:163:22: note: expanded from macro 'dynamic_pr_debug' pr_fmt(fmt), ##__VA_ARGS__) ^~~~~~~~~~~ include/linux/dynamic_debug.h:152:56: note: expanded from macro '_dynamic_func_call' __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__) ^~~~~~~~~~~ include/linux/dynamic_debug.h:134:15: note: expanded from macro '__dynamic_func_call' func(&id, ##__VA_ARGS__); \ ^~~~~~~~~~~ drivers/tty/n_gsm.c:1925:9: note: initialize the variable 'len' to silence this warning int len; ^ = 0 1 warning generated. vim +/len +1928 drivers/tty/n_gsm.c e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1907 e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1908 /** e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1909 * gsm_dlci_data - data arrived e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1910 * @dlci: channel e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1911 * @data: block of bytes received 724ac070ffc7a1 drivers/tty/n_gsm.c Jiri Slaby 2020-08-18 1912 * @clen: length of received block e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1913 * e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1914 * A UI or UIH frame has arrived which contains data for a channel e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1915 * other than the control channel. If the relevant virtual tty is e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1916 * open we shovel the bits down it, if not we drop them. e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1917 */ e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1918 4feb7a4a124444 drivers/tty/n_gsm.c Tony Lindgren 2019-01-13 1919 static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1920 { e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1921 /* krefs .. */ e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1922 struct tty_port *port = &dlci->port; 2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1923 struct tty_struct *tty; e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1924 unsigned int modem = 0; 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1925 int len; e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1926 e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1927 if (debug & 16) 2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 @1928 pr_debug("%d bytes for tty\n", len); e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1929 switch (dlci->adaption) { e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1930 /* Unsupported types */ 3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1931 case 4: /* Packetised interruptible data */ e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1932 break; 3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1933 case 3: /* Packetised uininterruptible voice/data */ e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1934 break; 3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1935 case 2: /* Asynchronous serial with line state in each frame */ 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1936 len = gsm_read_ea_val(&modem, data, clen); 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1937 if (len < 1) e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1938 return; 2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1939 tty = tty_port_tty_get(port); 2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1940 if (tty) { 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1941 gsm_process_modem(tty, dlci, modem, len); 1adf6fee58ca25 drivers/tty/n_gsm.c Daniel Starke 2022-04-14 1942 tty_wakeup(tty); 2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1943 tty_kref_put(tty); 2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1944 } 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1945 /* Skip processed modem data */ 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1946 data += len; 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1947 clen -= len; df561f6688fef7 drivers/tty/n_gsm.c Gustavo A. R. Silva 2020-08-23 1948 fallthrough; 3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1949 case 1: /* Line state will go via DLCI 0 controls only */ e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1950 default: 66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1951 tty_insert_flip_string(port, data, clen); 2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1952 tty_flip_buffer_push(port); e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1953 } e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1954 } e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1955 -- 0-DAY CI Kernel Test Service https://01.org/lkp