Hi Changbin, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v4.17-rc3 next-20180504] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/changbin-du-intel-com/kernel-hacking-GCC-optimization-for-better-debug-experience-Og/20180506-110946 config: arm64-allmodconfig (attached as .config) compiler: aarch64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=arm64 Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings All warnings (new ones prefixed by >>): drivers/pci/host/pci-xgene.c: In function 'xgene_pcie_setup_ib_reg': >> drivers/pci/host/pci-xgene.c:532:2: warning: 'pim_reg' may be used uninitialized in this function [-Wmaybe-uninitialized] xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1)); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- drivers/scsi/ufs/ufs-qcom.c: In function 'ufs_qcom_testbus_config': >> drivers/scsi/ufs/ufs-qcom.c:1527:6: warning: 'offset' may be used uninitialized in this function [-Wmaybe-uninitialized] int offset; ^~~~~~ >> drivers/scsi/ufs/ufs-qcom.c:1526:6: warning: 'reg' may be used uninitialized in this function [-Wmaybe-uninitialized] int reg; ^~~ vim +/pim_reg +532 drivers/pci/host/pci-xgene.c 5f6b6ccd Tanmay Inamdar 2014-10-01 484 5f6b6ccd Tanmay Inamdar 2014-10-01 485 static void xgene_pcie_setup_ib_reg(struct xgene_pcie_port *port, 5f6b6ccd Tanmay Inamdar 2014-10-01 486 struct of_pci_range *range, u8 *ib_reg_mask) 5f6b6ccd Tanmay Inamdar 2014-10-01 487 { 5f6b6ccd Tanmay Inamdar 2014-10-01 488 void __iomem *cfg_base = port->cfg_base; d963ab22 Bjorn Helgaas 2016-10-06 489 struct device *dev = port->dev; 5f6b6ccd Tanmay Inamdar 2014-10-01 490 void *bar_addr; 4ecf6b0f Bjorn Helgaas 2016-10-06 491 u32 pim_reg; 5f6b6ccd Tanmay Inamdar 2014-10-01 492 u64 cpu_addr = range->cpu_addr; 5f6b6ccd Tanmay Inamdar 2014-10-01 493 u64 pci_addr = range->pci_addr; 5f6b6ccd Tanmay Inamdar 2014-10-01 494 u64 size = range->size; 5f6b6ccd Tanmay Inamdar 2014-10-01 495 u64 mask = ~(size - 1) | EN_REG; 5f6b6ccd Tanmay Inamdar 2014-10-01 496 u32 flags = PCI_BASE_ADDRESS_MEM_TYPE_64; 5f6b6ccd Tanmay Inamdar 2014-10-01 497 u32 bar_low; 5f6b6ccd Tanmay Inamdar 2014-10-01 498 int region; 5f6b6ccd Tanmay Inamdar 2014-10-01 499 5f6b6ccd Tanmay Inamdar 2014-10-01 500 region = xgene_pcie_select_ib_reg(ib_reg_mask, range->size); 5f6b6ccd Tanmay Inamdar 2014-10-01 501 if (region < 0) { d963ab22 Bjorn Helgaas 2016-10-06 502 dev_warn(dev, "invalid pcie dma-range config\n"); 5f6b6ccd Tanmay Inamdar 2014-10-01 503 return; 5f6b6ccd Tanmay Inamdar 2014-10-01 504 } 5f6b6ccd Tanmay Inamdar 2014-10-01 505 5f6b6ccd Tanmay Inamdar 2014-10-01 506 if (range->flags & IORESOURCE_PREFETCH) 5f6b6ccd Tanmay Inamdar 2014-10-01 507 flags |= PCI_BASE_ADDRESS_MEM_PREFETCH; 5f6b6ccd Tanmay Inamdar 2014-10-01 508 5f6b6ccd Tanmay Inamdar 2014-10-01 509 bar_low = pcie_bar_low_val((u32)cpu_addr, flags); 5f6b6ccd Tanmay Inamdar 2014-10-01 510 switch (region) { 5f6b6ccd Tanmay Inamdar 2014-10-01 511 case 0: 4ecf6b0f Bjorn Helgaas 2016-10-06 512 xgene_pcie_set_ib_mask(port, BRIDGE_CFG_4, flags, size); 5f6b6ccd Tanmay Inamdar 2014-10-01 513 bar_addr = cfg_base + PCI_BASE_ADDRESS_0; 5f6b6ccd Tanmay Inamdar 2014-10-01 514 writel(bar_low, bar_addr); 5f6b6ccd Tanmay Inamdar 2014-10-01 515 writel(upper_32_bits(cpu_addr), bar_addr + 0x4); 4ecf6b0f Bjorn Helgaas 2016-10-06 516 pim_reg = PIM1_1L; 5f6b6ccd Tanmay Inamdar 2014-10-01 517 break; 5f6b6ccd Tanmay Inamdar 2014-10-01 518 case 1: 8e93c513 Bjorn Helgaas 2016-10-06 519 xgene_pcie_writel(port, IBAR2, bar_low); 8e93c513 Bjorn Helgaas 2016-10-06 520 xgene_pcie_writel(port, IR2MSK, lower_32_bits(mask)); 4ecf6b0f Bjorn Helgaas 2016-10-06 521 pim_reg = PIM2_1L; 5f6b6ccd Tanmay Inamdar 2014-10-01 522 break; 5f6b6ccd Tanmay Inamdar 2014-10-01 523 case 2: 8e93c513 Bjorn Helgaas 2016-10-06 524 xgene_pcie_writel(port, IBAR3L, bar_low); 8e93c513 Bjorn Helgaas 2016-10-06 525 xgene_pcie_writel(port, IBAR3L + 0x4, upper_32_bits(cpu_addr)); 8e93c513 Bjorn Helgaas 2016-10-06 526 xgene_pcie_writel(port, IR3MSKL, lower_32_bits(mask)); 8e93c513 Bjorn Helgaas 2016-10-06 527 xgene_pcie_writel(port, IR3MSKL + 0x4, upper_32_bits(mask)); 4ecf6b0f Bjorn Helgaas 2016-10-06 528 pim_reg = PIM3_1L; 5f6b6ccd Tanmay Inamdar 2014-10-01 529 break; 5f6b6ccd Tanmay Inamdar 2014-10-01 530 } 5f6b6ccd Tanmay Inamdar 2014-10-01 531 4ecf6b0f Bjorn Helgaas 2016-10-06 @532 xgene_pcie_setup_pims(port, pim_reg, pci_addr, ~(size - 1)); 5f6b6ccd Tanmay Inamdar 2014-10-01 533 } 5f6b6ccd Tanmay Inamdar 2014-10-01 534 :::::: The code at line 532 was first introduced by commit :::::: 4ecf6b0f83523fb186dd1de9e2f1d324a2a413d9 PCI: xgene: Pass struct xgene_pcie_port to setup functions :::::: TO: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> :::::: CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
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