Hi Bob, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on c9eeabac5e8d27a3f40280908e089058bab39edb] url: https://github.com/intel-lab-lkp/linux/commits/Bob-Pearson/RDMA-rxe-Enable-scatter-gather-support-for-skbs/20221028-025839 base: c9eeabac5e8d27a3f40280908e089058bab39edb patch link: https://lore.kernel.org/r/20221027185510.33808-15-rpearsonhpe%40gmail.com patch subject: [PATCH for-next 14/17] RDMA/rxe: Extend response packets for frags config: arm64-allyesconfig compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 791a7ae1ba3efd6bca96338e10ffde557ba83920) 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://github.com/intel-lab-lkp/linux/commit/36b2d4a5d83e1c9256d3b5fb3ce4989cac1e5ce9 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Bob-Pearson/RDMA-rxe-Enable-scatter-gather-support-for-skbs/20221028-025839 git checkout 36b2d4a5d83e1c9256d3b5fb3ce4989cac1e5ce9 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/infiniband/sw/rxe/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> drivers/infiniband/sw/rxe/rxe_resp.c:833:6: warning: variable 'state' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (err) ^~~ drivers/infiniband/sw/rxe/rxe_resp.c:868:9: note: uninitialized use occurs here return state; ^~~~~ drivers/infiniband/sw/rxe/rxe_resp.c:833:2: note: remove the 'if' if its condition is always false if (err) ^~~~~~~~ drivers/infiniband/sw/rxe/rxe_resp.c:771:2: note: variable 'state' is declared here enum resp_states state; ^ 1 warning generated. vim +833 drivers/infiniband/sw/rxe/rxe_resp.c 761 762 /* RDMA read response. If res is not NULL, then we have a current RDMA request 763 * being processed or replayed. 764 */ 765 static enum resp_states read_reply(struct rxe_qp *qp, 766 struct rxe_pkt_info *req_pkt) 767 { 768 struct rxe_pkt_info ack_pkt; 769 struct sk_buff *skb; 770 int mtu = qp->mtu; 771 enum resp_states state; 772 int payload; 773 int opcode; 774 int err; 775 struct resp_res *res = qp->resp.res; 776 struct rxe_mr *mr; 777 int skb_offset = 0; 778 bool frag; 779 enum rxe_mr_copy_op op; 780 781 if (!res) { 782 res = rxe_prepare_res(qp, req_pkt, RXE_READ_MASK); 783 qp->resp.res = res; 784 } 785 786 if (res->state == rdatm_res_state_new) { 787 if (!res->replay) { 788 mr = qp->resp.mr; 789 qp->resp.mr = NULL; 790 } else { 791 mr = rxe_recheck_mr(qp, res->read.rkey); 792 if (!mr) { 793 state = RESPST_ERR_RKEY_VIOLATION; 794 goto err_out; 795 } 796 } 797 798 if (res->read.resid <= mtu) 799 opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY; 800 else 801 opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST; 802 } else { 803 mr = rxe_recheck_mr(qp, res->read.rkey); 804 if (!mr) { 805 state = RESPST_ERR_RKEY_VIOLATION; 806 goto err_out; 807 } 808 809 if (res->read.resid > mtu) 810 opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE; 811 else 812 opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_LAST; 813 } 814 815 payload = min_t(int, res->read.resid, mtu); 816 817 skb = prepare_ack_packet(qp, &ack_pkt, opcode, payload, 818 res->cur_psn, AETH_ACK_UNLIMITED, &frag); 819 if (!skb) { 820 state = RESPST_ERR_RNR; 821 goto err_put_mr; 822 } 823 824 op = frag ? RXE_FRAG_FROM_MR : RXE_COPY_FROM_MR; 825 err = rxe_copy_mr_data(skb, mr, res->read.va, payload_addr(&ack_pkt), 826 skb_offset, payload, op); 827 if (err) { 828 state = RESPST_ERR_RKEY_VIOLATION; 829 goto err_free_skb; 830 } 831 832 err = rxe_prepare_pad_icrc(&ack_pkt, skb, payload, frag); > 833 if (err) 834 goto err_free_skb; 835 836 err = rxe_xmit_packet(qp, &ack_pkt, skb); 837 if (err) { 838 /* rxe_xmit_packet will consume the packet */ 839 state = RESPST_ERR_RNR; 840 goto err_put_mr; 841 } 842 843 res->read.va += payload; 844 res->read.resid -= payload; 845 res->cur_psn = (res->cur_psn + 1) & BTH_PSN_MASK; 846 847 if (res->read.resid > 0) { 848 state = RESPST_DONE; 849 } else { 850 qp->resp.res = NULL; 851 if (!res->replay) 852 qp->resp.opcode = -1; 853 if (psn_compare(res->cur_psn, qp->resp.psn) >= 0) 854 qp->resp.psn = res->cur_psn; 855 state = RESPST_CLEANUP; 856 } 857 858 /* keep these after all error exits */ 859 res->state = rdatm_res_state_next; 860 rxe_put(mr); 861 return state; 862 863 err_free_skb: 864 kfree_skb(skb); 865 err_put_mr: 866 rxe_put(mr); 867 err_out: 868 return state; 869 } 870 -- 0-DAY CI Kernel Test Service https://01.org/lkp