tree: https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git fuzzing_cleanup head: c4ec33c20414ce14307795bfab4eb3b83de76746 commit: 3cd55408d74d9c3a8547a52d2332f238cf8a2692 [7/8] xhci: add xhci_virt_ep_to_ring() helper config: alpha-randconfig-r021-20201217 (attached as .config) compiler: alpha-linux-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://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/commit/?i... git remote add xhci https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git git fetch --no-tags xhci fuzzing_cleanup git checkout 3cd55408d74d9c3a8547a52d2332f238cf8a2692 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=alpha 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 >>): drivers/usb/host/xhci-ring.c:449:22: warning: no previous prototype for 'xhci_get_virt_ep' [-Wmissing-prototypes] 449 | struct xhci_virt_ep *xhci_get_virt_ep(struct xhci_hcd *xhci, unsigned int slot_id, | ^~~~~~~~~~~~~~~~ 468 | struct xhci_ring *xhci_virt_ep_to_ring(struct xhci_hcd *xhci, | ^~~~~~~~~~~~~~~~~~~~ vim +/xhci_virt_ep_to_ring +468 drivers/usb/host/xhci-ring.c 467 469 struct xhci_virt_ep *ep, 470 unsigned int stream_id) 471 { 472 /* common case, no streams */ 473 if (!(ep->ep_state & EP_HAS_STREAMS)) 474 return ep->ring; 475 476 if (!ep->stream_info) 477 return NULL; 478 479 if (stream_id == 0 || stream_id >= ep->stream_info->num_streams) { 480 xhci_warn(xhci, "Invalid stream %u request for slot %u ep %u\n", 481 ep->vdev->slot_id, ep->ep_index, stream_id); 482 return NULL; 483 } 484 485 return ep->stream_info->stream_rings[stream_id]; 486 } 487 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org