Hi Geert, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 5695e51619745d4fe3ec2506a2f0cd982c5e27a4 commit: ade896460e4a62f5e4a892a98d254937f6f5b64c drm: DRM_KMB_DISPLAY should depend on ARCH_KEEMBAY date: 4 months ago config: mips-randconfig-r004-20210228 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 83bc7815c4235786111aa2abf7193292e4a602f5) 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 mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout ade896460e4a62f5e4a892a98d254937f6f5b64c # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): set_test_mode_src_osc_freq_target_low_bits(struct kmb_dsi ^ set_test_mode_src_osc_freq_target_hi_bits(struct kmb_dsi ^ fatal error: error in backend: Nested variants found in inline asm string: '.if ( 0x00 ) != -1)) 0x00 ) != -1)) : ($( static struct ftrace_branch_data __attribute__((__aligned__(4))) __attribute__((__section__("_ftrace_branch"))) __if_trace = $( .func = __func__, .file = "arch/mips/include/asm/barrier.h", .line = 16, $); 0x00 ) != -1)) : $))) ) && ( (1 << 0) ); .set push; .set mips64r2; .rept 1; sync 0x00; .endr; .set pop; .else; ; .endif' clang-13: error: clang frontend command failed with exit code 70 (use -v to see invocation) clang version 13.0.0 (git://gitmirror/llvm_project 83bc7815c4235786111aa2abf7193292e4a602f5) Target: mipsel-unknown-linux-gnu Thread model: posix InstalledDir: /opt/cross/clang-83bc7815c4/bin clang-13: note: diagnostic msg: Makefile arch drivers fs include kernel mm scripts security source usr vim +/set_test_mode_src_osc_freq_target_low_bits +812 drivers/gpu/drm/kmb/kmb_dsi.c 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 810 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 811 static inline void 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 @812 set_test_mode_src_osc_freq_target_low_bits(struct kmb_dsi *kmb_dsi, 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 813 u32 dphy_no, 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 814 u32 freq) 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 815 { 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 816 /* Typical rise/fall time=166, refer Table 1207 databook, 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 817 * sr_osc_freq_target[7:0] 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 818 */ 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 819 test_mode_send(kmb_dsi, dphy_no, TEST_CODE_SLEW_RATE_DDL_CYCLES, 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 820 (freq & 0x7f)); 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 821 } 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 822 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 823 static inline void 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 @824 set_test_mode_src_osc_freq_target_hi_bits(struct kmb_dsi *kmb_dsi, 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 825 u32 dphy_no, 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 826 u32 freq) 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 827 { 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 828 u32 data; 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 829 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 830 /* Flag this as high nibble */ 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 831 data = ((freq >> 6) & 0x1f) | (1 << 7); 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 832 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 833 /* Typical rise/fall time=166, refer Table 1207 databook, 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 834 * sr_osc_freq_target[11:7] 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 835 */ 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 836 test_mode_send(kmb_dsi, dphy_no, TEST_CODE_SLEW_RATE_DDL_CYCLES, data); 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 837 } 98521f4d4b4cb2 Anitha Chrisanthus 2020-11-04 838 :::::: The code at line 812 was first introduced by commit :::::: 98521f4d4b4cb265374a4b1e13b41287a1960243 drm/kmb: Mipi DSI part of the display driver :::::: TO: Anitha Chrisanthus <anitha.chrisanthus(a)intel.com&gt; :::::: CC: Sam Ravnborg <sam(a)ravnborg.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org