Hi Sergey, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on char-misc/char-misc-testing] [also build test WARNING on linux/master linus/master v5.10 next-20201215] [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/Sergey-Temerkhanov/tpm-Rework-open-close-shutdown-to-avoid-races/20201215-214304 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git 93f998879cd95b3e4f2836e7b17d6d5ae035cf90 config: m68k-randconfig-r012-20201215 (attached as .config) compiler: m68k-linux-gcc (GCC) 9.3.0 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/b1f6f05f320b6b609ff70567a701e12504783b02 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Sergey-Temerkhanov/tpm-Rework-open-close-shutdown-to-avoid-races/20201215-214304 git checkout b1f6f05f320b6b609ff70567a701e12504783b02 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): drivers/char/tpm/tpm-dev.c: In function 'tpm_open': >> drivers/char/tpm/tpm-dev.c:22:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable] 22 | int ret = 0; | ^~~ vim +/ret +22 drivers/char/tpm/tpm-dev.c 17 18 static int tpm_open(struct inode *inode, struct file *file) 19 { 20 struct tpm_chip *chip; 21 struct file_priv *priv; > 22 int ret = 0; 23 24 chip = container_of(inode->i_cdev, struct tpm_chip, cdev); 25 26 /* It's assured that the chip will be opened just once, 27 * by the check of the chip reference count. 28 */ 29 if (atomic_fetch_inc(&chip->refcount)) { 30 dev_dbg(&chip->dev, "Another process owns this TPM\n"); 31 ret = -EBUSY; 32 goto out; 33 } 34 35 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 36 if (priv == NULL) { 37 ret = -ENOMEM; 38 goto out; 39 } 40 41 tpm_common_open(file, chip, priv, NULL); 42 43 return 0; 44 45 out: 46 atomic_dec(&chip->refcount); 47 wake_up_all(&chip->waitq); 48 return -ENOMEM; 49 } 50 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org