tree: https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git rewrite_invalid_context_at_stop_endpoint head: eae681e2e11a3d370aedbafd618422b0f57c3600 commit: c60e0cbd4157a3742834fb57a2cb5bf9d9fc42c1 [6/7] xhci: introduce a new move_dequeue_past_td() function to replace old code. config: arm64-randconfig-r021-20201019 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 094e9f4779eb9b5c6a49014f2f80b8cbb833572f) 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 arm64 cross compiling tool for clang build # apt-get install binutils-aarch64-linux-gnu # 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 rewrite_invalid_context_at_stop_endpoint git checkout c60e0cbd4157a3742834fb57a2cb5bf9d9fc42c1 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 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 >>): int xhci_move_dequeue_past_td(struct xhci_hcd *xhci, ^ drivers/usb/host/xhci-ring.c:635:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int xhci_move_dequeue_past_td(struct xhci_hcd *xhci, ^ static 1 warning generated. vim +/xhci_move_dequeue_past_td +635 drivers/usb/host/xhci-ring.c 634 636 unsigned int slot_id, unsigned int ep_index, 637 unsigned int stream_id, struct xhci_td *td) 638 { 639 struct xhci_virt_device *dev = xhci->devs[slot_id]; 640 struct xhci_virt_ep *ep = &dev->eps[ep_index]; 641 struct xhci_ring *ep_ring; 642 struct xhci_command *cmd; 643 struct xhci_segment *new_seg; 644 union xhci_trb *new_deq; 645 int new_cycle; 646 dma_addr_t addr; 647 u64 hw_dequeue; 648 bool cycle_found = false; 649 bool td_last_trb_found = false; 650 u32 trb_sct = 0; 651 int ret; 652 653 ep_ring = xhci_triad_to_transfer_ring(xhci, slot_id, 654 ep_index, stream_id); 655 if (!ep_ring) { 656 xhci_warn(xhci, "WARN can't find new dequeue state " 657 "for invalid stream ID %u.\n", 658 stream_id); 659 return -ENODEV; 660 } 661 /* 662 * A cancelled TD can complete with a stall if HW cached the trb. 663 * In this case driver can't find td, but if the ring is empty we 664 * can move the dequeue pointer to the current enqueue position. 665 * FIXMA MATTU is this still the case? 666 */ 667 if (!td) { 668 if (list_empty(&ep_ring->td_list)) { 669 new_seg = ep_ring->enq_seg; 670 new_deq = ep_ring->enqueue; 671 new_cycle = ep_ring->cycle_state; 672 xhci_dbg(xhci, "ep ring empty, Set new dequeue = enqueue"); 673 goto deq_found; 674 } else { 675 xhci_warn(xhci, "Can't find new dequeue state, missing td\n"); 676 return -EINVAL; 677 } 678 } 679 680 hw_dequeue = xhci_get_hw_deq(xhci, dev, ep_index, stream_id); 681 new_seg = ep_ring->deq_seg; 682 new_deq = ep_ring->dequeue; 683 new_cycle = hw_dequeue & 0x1; 684 685 /* 686 * We want to find the pointer, segment and cycle state of the new trb 687 * (the one after current TD's last_trb). We know the cycle state at 688 * hw_dequeue, so walk the ring until both hw_dequeue and last_trb are 689 * found. 690 */ 691 do { 692 if (!cycle_found && xhci_trb_virt_to_dma(new_seg, new_deq) 693 == (dma_addr_t)(hw_dequeue & ~0xf)) { 694 cycle_found = true; 695 if (td_last_trb_found) 696 break; 697 } 698 if (new_deq == td->last_trb) 699 td_last_trb_found = true; 700 701 if (cycle_found && trb_is_link(new_deq) && 702 link_trb_toggles_cycle(new_deq)) 703 new_cycle ^= 0x1; 704 705 next_trb(xhci, ep_ring, &new_seg, &new_deq); 706 707 /* Search wrapped around, bail out */ 708 if (new_deq == ep->ring->dequeue) { 709 xhci_err(xhci, "Error: Failed finding new dequeue state\n"); 710 return -EINVAL; 711 } 712 713 } while (!cycle_found || !td_last_trb_found); 714 715 deq_found: 716 717 /* Don't update the ring cycle state for the producer (us). */ 718 addr = xhci_trb_virt_to_dma(new_seg, new_deq); 719 if (addr == 0) { 720 xhci_warn(xhci, "WARN Cannot find dma of new dequeue ptr\n"); 721 xhci_warn(xhci, "deq seg = %p, deq ptr = %p\n", new_seg, new_deq); 722 return -EINVAL; 723 } 724 725 /* MATTU fixme do we want this PENDING flag at all?*/ 726 if ((ep->ep_state & SET_DEQ_PENDING)) { 727 xhci_warn(xhci, "WARN Can't submit Set TR Deq 0x%llx\n", addr); 728 xhci_warn(xhci, "Another Set TR Deq command is pending.\n"); 729 return -EBUSY; //MATTU FIXME 730 } 731 732 /* This function gets called from contexts where it cannot sleep */ 733 cmd = xhci_alloc_command(xhci, false, GFP_ATOMIC); 734 if (!cmd) { 735 xhci_warn(xhci, "WARN Fail to allocate Set TR Deq cmd 0x%llx\n", addr); 736 return -ENOMEM; 737 } 738 739 if (stream_id) 740 trb_sct = SCT_FOR_TRB(SCT_PRI_TR); 741 ret = queue_command(xhci, cmd, 742 lower_32_bits(addr) | trb_sct | new_cycle, 743 upper_32_bits(addr), 744 STREAM_ID_FOR_TRB(stream_id), SLOT_ID_FOR_TRB(slot_id) | 745 EP_ID_FOR_TRB(ep_index) | TRB_TYPE(TRB_SET_DEQ), false); 746 if (ret < 0) { 747 xhci_free_command(xhci, cmd); 748 return ret; 749 } 750 751 ep->queued_deq_seg = new_seg; 752 ep->queued_deq_ptr = new_deq; 753 754 xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb, 755 "Set TR Deq ptr 0x%llx, cycle %u\n", addr, new_cycle); 756 757 /* Stop the TD queueing code from ringing the doorbell until 758 * this command completes. The HC won't set the dequeue pointer 759 * if the ring is running, and ringing the doorbell starts the 760 * ring running. 761 */ 762 ep->ep_state |= SET_DEQ_PENDING; 763 return 0; 764 } 765 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org