Hi Chunfeng, I love your patch! Perhaps something to improve: [auto build test WARNING on usb/usb-testing] [also build test WARNING on v5.13-rc6 next-20210616] [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/Chunfeng-Yun/usb-xhci-mtk-allow-multiple-Start-Split-in-a-microframe/20210617-101730 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing config: arc-allyesconfig (attached as .config) compiler: arceb-elf-gcc (GCC) 9.3.0 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 # https://github.com/0day-ci/linux/commit/1417adf315cfee06ef79bd1e34266e9098863b5c git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Chunfeng-Yun/usb-xhci-mtk-allow-multiple-Start-Split-in-a-microframe/20210617-101730 git checkout 1417adf315cfee06ef79bd1e34266e9098863b5c # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): drivers/usb/host/xhci-mtk-sch.c: In function 'update_sch_tt': >> drivers/usb/host/xhci-mtk-sch.c:538:6: warning: variable 'bits' set but not used [-Wunused-but-set-variable] 538 | int bits; | ^~~~ vim +/bits +538 drivers/usb/host/xhci-mtk-sch.c 08e469de87a253 Chunfeng Yun 2018-09-20 532 6009bea08ad79c Chunfeng Yun 2021-03-08 533 static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used) 08e469de87a253 Chunfeng Yun 2018-09-20 534 { 08e469de87a253 Chunfeng Yun 2018-09-20 535 struct mu3h_sch_tt *tt = sch_ep->sch_tt; 08e469de87a253 Chunfeng Yun 2018-09-20 536 u32 base, num_esit; e19ee44a3d07c2 Chunfeng Yun 2021-03-08 537 int bw_updated; e19ee44a3d07c2 Chunfeng Yun 2021-03-08 @538 int bits; 08e469de87a253 Chunfeng Yun 2018-09-20 539 int i, j; 08e469de87a253 Chunfeng Yun 2018-09-20 540 08e469de87a253 Chunfeng Yun 2018-09-20 541 num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit; e19ee44a3d07c2 Chunfeng Yun 2021-03-08 542 bits = (sch_ep->ep_type == ISOC_OUT_EP) ? sch_ep->cs_count : 1; e19ee44a3d07c2 Chunfeng Yun 2021-03-08 543 e19ee44a3d07c2 Chunfeng Yun 2021-03-08 544 if (used) e19ee44a3d07c2 Chunfeng Yun 2021-03-08 545 bw_updated = sch_ep->bw_cost_per_microframe; e19ee44a3d07c2 Chunfeng Yun 2021-03-08 546 else e19ee44a3d07c2 Chunfeng Yun 2021-03-08 547 bw_updated = -sch_ep->bw_cost_per_microframe; e19ee44a3d07c2 Chunfeng Yun 2021-03-08 548 08e469de87a253 Chunfeng Yun 2018-09-20 549 for (i = 0; i < num_esit; i++) { 08e469de87a253 Chunfeng Yun 2018-09-20 550 base = sch_ep->offset + i * sch_ep->esit; e19ee44a3d07c2 Chunfeng Yun 2021-03-08 551 e19ee44a3d07c2 Chunfeng Yun 2021-03-08 552 for (j = 0; j < sch_ep->cs_count; j++) e19ee44a3d07c2 Chunfeng Yun 2021-03-08 553 tt->fs_bus_bw[base + j] += bw_updated; 08e469de87a253 Chunfeng Yun 2018-09-20 554 } 08e469de87a253 Chunfeng Yun 2018-09-20 555 e19ee44a3d07c2 Chunfeng Yun 2021-03-08 556 if (used) 08e469de87a253 Chunfeng Yun 2018-09-20 557 list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list); e19ee44a3d07c2 Chunfeng Yun 2021-03-08 558 else e19ee44a3d07c2 Chunfeng Yun 2021-03-08 559 list_del(&sch_ep->tt_endpoint); 08e469de87a253 Chunfeng Yun 2018-09-20 560 } 08e469de87a253 Chunfeng Yun 2018-09-20 561 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org