Hi Daniel, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 94f0b2d4a1d0c52035aef425da5e022bd2cb1c71 commit: f90cf6079bf67988f8b1ad1ade70fc89d0080905 media: vidtv: add a bridge driver date: 9 months ago config: powerpc64-randconfig-r026-20210615 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 64720f57bea6a6bf033feef4a5751ab9c0c3b401) 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 # 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 f90cf6079bf67988f8b1ad1ade70fc89d0080905 # 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 >>): In file included from drivers/media/test-drivers/vidtv/vidtv_mux.c:18: In file included from include/linux/slab.h:15: In file included from include/linux/gfp.h:5: In file included from include/linux/mmdebug.h:5: In file included from include/linux/bug.h:5: In file included from arch/powerpc/include/asm/bug.h:109: In file included from include/asm-generic/bug.h:20: In file included from include/linux/kernel.h:12: In file included from include/linux/bitops.h:29: In file included from arch/powerpc/include/asm/bitops.h:62: arch/powerpc/include/asm/barrier.h:49:9: warning: '__lwsync' macro redefined [-Wmacro-redefined] #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") ^ <built-in>:309:9: note: previous definition is here #define __lwsync __builtin_ppc_lwsync ^ static void vidtv_mux_tick(struct work_struct *work) ^ 2 warnings generated. vim +/vidtv_mux_tick +379 drivers/media/test-drivers/vidtv/vidtv_mux.c 378 380 { 381 struct vidtv_mux *m = container_of(work, 382 struct vidtv_mux, 383 mpeg_thread); 384 u32 nbytes; 385 u32 npkts; 386 387 while (m->streaming) { 388 nbytes = 0; 389 390 vidtv_mux_update_clk(m); 391 392 if (vidtv_mux_should_push_pcr(m)) 393 nbytes += vidtv_mux_push_pcr(m); 394 395 if (vidtv_mux_should_push_si(m)) 396 nbytes += vidtv_mux_push_si(m); 397 398 nbytes += vidtv_mux_poll_encoders(m); 399 nbytes += vidtv_mux_check_mux_rate(m); 400 401 npkts = nbytes / TS_PACKET_LEN; 402 403 /* if the buffer is not aligned there is a bug somewhere */ 404 if (nbytes % TS_PACKET_LEN) 405 pr_err_ratelimited("Misaligned buffer\n"); 406 407 if (m->on_new_packets_available_cb) 408 m->on_new_packets_available_cb(m->priv, 409 m->mux_buf, 410 npkts); 411 412 vidtv_mux_clear(m); 413 414 usleep_range(VIDTV_SLEEP_USECS, VIDTV_MAX_SLEEP_USECS); 415 } 416 } 417 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org