Hi Krishna, kernel test robot noticed the following build warnings: [auto build test WARNING on 0ad2507d5d93f39619fc42372c347d6006b64319] url: https://github.com/intel-lab-lkp/linux/commits/Krishna-Chaitanya-Chundru/PCI-update-current-bus-speed-as-part-of-pci_bus_add_devices/20250217-144050 base: 0ad2507d5d93f39619fc42372c347d6006b64319 patch link: https://lore.kernel.org/r/20250217-mhi_bw_up-v1-6-9bad1e42bdb1%40oss.qualcomm.com patch subject: [PATCH 6/8] bus: mhi: host: Add support for Bandwidth scale config: x86_64-buildonly-randconfig-006-20250217 (https://download.01.org/0day-ci/archive/20250217/202502171823.5VC7a1E6-lkp@xxxxxxxxx/config) compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250217/202502171823.5VC7a1E6-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202502171823.5VC7a1E6-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> drivers/bus/mhi/host/init.c:682:6: warning: variable 'doorbell' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] 682 | if (mhi_cntrl->get_misc_doorbell) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/bus/mhi/host/init.c:685:6: note: uninitialized use occurs here 685 | if (doorbell > 0) { | ^~~~~~~~ drivers/bus/mhi/host/init.c:682:2: note: remove the 'if' if its condition is always true 682 | if (mhi_cntrl->get_misc_doorbell) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 683 | doorbell = mhi_cntrl->get_misc_doorbell(mhi_cntrl, MHI_ER_BW_SCALE); drivers/bus/mhi/host/init.c:548:22: note: initialize the variable 'doorbell' to silence this warning 548 | int i, ret, doorbell; | ^ | = 0 1 warning generated. vim +682 drivers/bus/mhi/host/init.c 544 545 int mhi_init_mmio(struct mhi_controller *mhi_cntrl) 546 { 547 u32 val; 548 int i, ret, doorbell; 549 struct mhi_chan *mhi_chan; 550 struct mhi_event *mhi_event; 551 void __iomem *base = mhi_cntrl->regs; 552 struct device *dev = &mhi_cntrl->mhi_dev->dev; 553 struct { 554 u32 offset; 555 u32 val; 556 } reg_info[] = { 557 { 558 CCABAP_HIGHER, 559 upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr), 560 }, 561 { 562 CCABAP_LOWER, 563 lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr), 564 }, 565 { 566 ECABAP_HIGHER, 567 upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr), 568 }, 569 { 570 ECABAP_LOWER, 571 lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr), 572 }, 573 { 574 CRCBAP_HIGHER, 575 upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr), 576 }, 577 { 578 CRCBAP_LOWER, 579 lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr), 580 }, 581 { 582 MHICTRLBASE_HIGHER, 583 upper_32_bits(mhi_cntrl->iova_start), 584 }, 585 { 586 MHICTRLBASE_LOWER, 587 lower_32_bits(mhi_cntrl->iova_start), 588 }, 589 { 590 MHIDATABASE_HIGHER, 591 upper_32_bits(mhi_cntrl->iova_start), 592 }, 593 { 594 MHIDATABASE_LOWER, 595 lower_32_bits(mhi_cntrl->iova_start), 596 }, 597 { 598 MHICTRLLIMIT_HIGHER, 599 upper_32_bits(mhi_cntrl->iova_stop), 600 }, 601 { 602 MHICTRLLIMIT_LOWER, 603 lower_32_bits(mhi_cntrl->iova_stop), 604 }, 605 { 606 MHIDATALIMIT_HIGHER, 607 upper_32_bits(mhi_cntrl->iova_stop), 608 }, 609 { 610 MHIDATALIMIT_LOWER, 611 lower_32_bits(mhi_cntrl->iova_stop), 612 }, 613 {0, 0} 614 }; 615 616 dev_dbg(dev, "Initializing MHI registers\n"); 617 618 /* Read channel db offset */ 619 ret = mhi_get_channel_doorbell_offset(mhi_cntrl, &val); 620 if (ret) 621 return ret; 622 623 if (val >= mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)) { 624 dev_err(dev, "CHDB offset: 0x%x is out of range: 0x%zx\n", 625 val, mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)); 626 return -ERANGE; 627 } 628 629 /* Setup wake db */ 630 mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB); 631 mhi_cntrl->wake_set = false; 632 633 /* Setup channel db address for each channel in tre_ring */ 634 mhi_chan = mhi_cntrl->mhi_chan; 635 for (i = 0; i < mhi_cntrl->max_chan; i++, val += 8, mhi_chan++) 636 mhi_chan->tre_ring.db_addr = base + val; 637 638 /* Read event ring db offset */ 639 ret = mhi_read_reg(mhi_cntrl, base, ERDBOFF, &val); 640 if (ret) { 641 dev_err(dev, "Unable to read ERDBOFF register\n"); 642 return -EIO; 643 } 644 645 if (val >= mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings)) { 646 dev_err(dev, "ERDB offset: 0x%x is out of range: 0x%zx\n", 647 val, mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings)); 648 return -ERANGE; 649 } 650 651 /* Setup event db address for each ev_ring */ 652 mhi_event = mhi_cntrl->mhi_event; 653 for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) { 654 if (mhi_event->offload_ev) 655 continue; 656 657 mhi_event->ring.db_addr = base + val; 658 } 659 660 /* Setup DB register for primary CMD rings */ 661 mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER; 662 663 /* Write to MMIO registers */ 664 for (i = 0; reg_info[i].offset; i++) 665 mhi_write_reg(mhi_cntrl, base, reg_info[i].offset, 666 reg_info[i].val); 667 668 ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NER_MASK, 669 mhi_cntrl->total_ev_rings); 670 if (ret) { 671 dev_err(dev, "Unable to write MHICFG register\n"); 672 return ret; 673 } 674 675 ret = mhi_write_reg_field(mhi_cntrl, base, MHICFG, MHICFG_NHWER_MASK, 676 mhi_cntrl->hw_ev_rings); 677 if (ret) { 678 dev_err(dev, "Unable to write MHICFG register\n"); 679 return ret; 680 } 681 > 682 if (mhi_cntrl->get_misc_doorbell) 683 doorbell = mhi_cntrl->get_misc_doorbell(mhi_cntrl, MHI_ER_BW_SCALE); 684 685 if (doorbell > 0) { 686 ret = mhi_init_bw_scale(mhi_cntrl, doorbell); 687 if (!ret) 688 mhi_cntrl->bw_scale_db = base + val + (8 * doorbell); 689 else 690 dev_warn(dev, "BW scale setup failure\n"); 691 } 692 return 0; 693 } 694 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
