tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 7ce53e3a447bced7b85ed181c4d027e93c062e07 commit: 36cfd3a6e52bd65d42b1d04fbff30ac427f80cbd [6411/6654] net: mvpp2: restructure "link status" interrupt handling config: powerpc64-randconfig-r011-20200909 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 0a5dc7effb191eff740e0e7ae7bd8e1f6bdb3ad9) 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 powerpc64 cross compiling tool for clang build # apt-get install binutils-powerpc64-linux-gnu git checkout 36cfd3a6e52bd65d42b1d04fbff30ac427f80cbd # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 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 >>): if (val & MVPP22_XLG_STATUS_LINK_UP) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3016:31: note: uninitialized use occurs here mvpp2_isr_handle_link(port, link); ^~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3014:3: note: remove the 'if' if its condition is always true if (val & MVPP22_XLG_STATUS_LINK_UP) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3008:11: note: initialize the variable 'link' to silence this warning bool link; ^ = 0 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3031:8: warning: variable 'link' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (val & MVPP2_GMAC_STATUS0_LINK_UP) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3033:32: note: uninitialized use occurs here mvpp2_isr_handle_link(port, link); ^~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3031:4: note: remove the 'if' if its condition is always true if (val & MVPP2_GMAC_STATUS0_LINK_UP) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:3022:11: note: initialize the variable 'link' to silence this warning bool link; ^ = 0 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c:6785:36: warning: unused variable 'mvpp2_acpi_match' [-Wunused-const-variable] static const struct acpi_device_id mvpp2_acpi_match[] = { ^ 3 warnings generated. # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 36cfd3a6e52bd65d42b1d04fbff30ac427f80cbd vim +3014 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3005 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3006 static void mvpp2_isr_handle_xlg(struct mvpp2_port *port) 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3007 { 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3008 bool link; 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3009 u32 val; fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c Antoine Tenart 2017-09-01 3010 fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c Antoine Tenart 2017-09-01 3011 val = readl(port->base + MVPP22_XLG_INT_STAT); fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c Antoine Tenart 2017-09-01 3012 if (val & MVPP22_XLG_INT_STAT_LINK) { fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c Antoine Tenart 2017-09-01 3013 val = readl(port->base + MVPP22_XLG_STATUS); fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c Antoine Tenart 2017-09-01 @3014 if (val & MVPP22_XLG_STATUS_LINK_UP) fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c Antoine Tenart 2017-09-01 3015 link = true; 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3016 mvpp2_isr_handle_link(port, link); fd3651b2ab66de drivers/net/ethernet/marvell/mvpp2.c Antoine Tenart 2017-09-01 3017 } 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3018 } 36cfd3a6e52bd6 drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c Russell King 2020-09-09 3019 :::::: The code at line 3014 was first introduced by commit :::::: fd3651b2ab66de177ad0d51c239af260a764b9f1 net: mvpp2: use the GoP interrupt for link status changes :::::: TO: Antoine Tenart <antoine.tenart(a)free-electrons.com&gt; :::::: CC: David S. Miller <davem(a)davemloft.net&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org