Hi Arnd, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git randconfig-v5.12 head: fd21c2581b744639b5207c11651ab40abf13701a commit: c43a5a05c0cd6cc79fa4cf9400d94faf4f663b6f [323/597] fixup warnings config: sparc64-randconfig-s031-20210318 (attached as .config) compiler: sparc64-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.3-277-gc089cd2d-dirty # https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/commi... git remote add arnd-playground https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git git fetch --no-tags arnd-playground randconfig-v5.12 git checkout c43a5a05c0cd6cc79fa4cf9400d94faf4f663b6f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=sparc64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) drivers/soc/ixp4xx/ixp4xx-qmgr.c:153:40: sparse: sparse: dereference of noderef expression drivers/soc/ixp4xx/ixp4xx-qmgr.c:154:40: sparse: sparse: dereference of noderef expression drivers/soc/ixp4xx/ixp4xx-qmgr.c:174:38: sparse: sparse: dereference of noderef expression drivers/soc/ixp4xx/ixp4xx-qmgr.c:174:44: sparse: sparse: dereference of noderef expression vim +149 drivers/soc/ixp4xx/ixp4xx-qmgr.c 82a96f5790ac93 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Halasa 2008-01-01 139 82a96f5790ac93 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Halasa 2008-01-01 140 d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 141 static irqreturn_t qmgr_irq1_a0(int irq, void *pdev) d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 142 { d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 143 int i, ret = 0; 0771c6939484d2 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-04-28 144 u32 en_bitmap, src, stat; d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 145 d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 146 /* ACK - it may clear any bits so don't rely on it */ d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 147 __raw_writel(0xFFFFFFFF, &qmgr_regs->irqstat[0]); d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 148 0771c6939484d2 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-04-28 @149 en_bitmap = qmgr_regs->irqen[0]; 0771c6939484d2 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-04-28 150 while (en_bitmap) { 0771c6939484d2 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-04-28 151 i = __fls(en_bitmap); /* number of the last "low" queue */ 0771c6939484d2 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-04-28 152 en_bitmap &= ~BIT(i); d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 153 src = qmgr_regs->irqsrc[i >> 3]; d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 154 stat = qmgr_regs->stat1[i >> 3]; d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 155 if (src & 4) /* the IRQ condition is inverted */ d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 156 stat = ~stat; d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 157 if (stat & BIT(src & 3)) { d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 158 irq_handlers[i](irq_pdevs[i]); d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 159 ret = IRQ_HANDLED; d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 160 } d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 161 } d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 162 return ret; d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 163 } d4c9e9fc975155 arch/arm/mach-ixp4xx/ixp4xx_qmgr.c Krzysztof Hałasa 2009-05-23 164 :::::: The code at line 149 was first introduced by commit :::::: 0771c6939484d2ebe0ec28257c2570aecd9911e0 IXP42x: Use __fls() in QMgr interrupt handlers. :::::: TO: Krzysztof Hałasa <khc(a)pm.waw.pl&gt; :::::: CC: Krzysztof Hałasa <khc(a)pm.waw.pl&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org