Hi Parshuram, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on robh/for-next] [also build test WARNING on linux/master linus/master v5.12-rc3 next-20210317] [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/Parshuram-Thombare/enable-HDCP-in-Cadence-MHDP-bridge-driver/20210318-000928 base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next config: x86_64-randconfig-a016-20210317 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 8ef111222a3dd12a9175f69c3bff598c46e8bdf7) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/0day-ci/linux/commit/9c8eb15a5059a553e08304619775dd7af4394eb1 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Parshuram-Thombare/enable-HDCP-in-Cadence-MHDP-bridge-driver/20210318-000928 git checkout 9c8eb15a5059a553e08304619775dd7af4394eb1 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c:502:5: warning: no previous prototype for function 'cdns_mhdp_hdcp_set_lc' [-Wmissing-prototypes] int cdns_mhdp_hdcp_set_lc(struct cdns_mhdp_device *mhdp, u8 *val) ^ drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c:502:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int cdns_mhdp_hdcp_set_lc(struct cdns_mhdp_device *mhdp, u8 *val) ^ static >> drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c:516:1: warning: no previous prototype for function 'cdns_mhdp_hdcp_set_public_key_params' [-Wmissing-prototypes] cdns_mhdp_hdcp_set_public_key_params(struct cdns_mhdp_device *mhdp, ^ drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c:515:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int ^ static 2 warnings generated. vim +/cdns_mhdp_hdcp_set_lc +502 drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.c 501 > 502 int cdns_mhdp_hdcp_set_lc(struct cdns_mhdp_device *mhdp, u8 *val) 503 { 504 int ret; 505 506 mutex_lock(&mhdp->mbox_mutex); 507 ret = cdns_mhdp_secure_mailbox_send(mhdp, MB_MODULE_ID_HDCP_GENERAL, 508 HDCP_GENERAL_SET_LC_128, 509 16, val); 510 mutex_unlock(&mhdp->mbox_mutex); 511 512 return ret; 513 } 514 515 int > 516 cdns_mhdp_hdcp_set_public_key_params(struct cdns_mhdp_device *mhdp, 517 struct cdns_hdcp_tx_public_key_param *val) 518 { 519 int ret; 520 521 mutex_lock(&mhdp->mbox_mutex); 522 ret = cdns_mhdp_secure_mailbox_send(mhdp, MB_MODULE_ID_HDCP_TX, 523 HDCP2X_TX_SET_PUBLIC_KEY_PARAMS, 524 sizeof(*val), (u8 *)val); 525 mutex_unlock(&mhdp->mbox_mutex); 526 527 return ret; 528 } 529 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org