The driver may sleep with holding a spinlock and in an interupt handler. The function call paths (from bottom to top) in Linux-4.16 are: [FUNC] usleep_range drivers/pci/dwc/pcie-designware.c, 181: usleep_range in dw_pcie_prog_outbound_atu drivers/pci/dwc/pcie-designware-host.c, 479: dw_pcie_prog_outbound_atu in dw_pcie_rd_other_conf drivers/pci/dwc/pcie-designware-host.c, 561: dw_pcie_rd_other_conf in dw_pcie_rd_conf drivers/pci/access.c, 66: [FUNC_PTR]dw_pcie_rd_conf in pci_bus_read_config_word drivers/pci/access.c, 918: pci_bus_read_config_word in pci_read_config_word drivers/block/umem.c, 630: pci_read_config_word in mm_interrupt (interrupt handler) [FUNC] usleep_range drivers/pci/dwc/pcie-designware.c, 181: usleep_range in dw_pcie_prog_outbound_atu drivers/pci/dwc/pcie-designware-host.c, 479: dw_pcie_prog_outbound_atu in dw_pcie_rd_other_conf drivers/pci/dwc/pcie-designware-host.c, 561: dw_pcie_rd_other_conf in dw_pcie_rd_conf drivers/pci/access.c, 66: [FUNC_PTR]dw_pcie_rd_conf in pci_bus_read_config_word drivers/pci/access.c, 918: pci_bus_read_config_word in pci_read_config_word drivers/ata/pata_efar.c, 115: pci_read_config_word in efar_set_piomode drivers/ata/pata_efar.c, 113: _raw_spin_lock_irqsave in efar_set_piomod [FUNC] usleep_range drivers/pci/dwc/pcie-designware.c, 181: usleep_range in dw_pcie_prog_outbound_atu drivers/pci/dwc/pcie-designware-host.c, 479: dw_pcie_prog_outbound_atu in dw_pcie_rd_other_conf drivers/pci/dwc/pcie-designware-host.c, 561: dw_pcie_rd_other_conf in dw_pcie_rd_conf drivers/pci/access.c, 66: [FUNC_PTR]dw_pcie_rd_conf in pci_bus_read_config_word drivers/pci/access.c, 918: pci_bus_read_config_word in pci_read_config_word drivers/block/mtip32xx/mtip32xx.c, 158: pci_read_config_word in mtip_check_surprise_removal drivers/block/mtip32xx/mtip32xx.c, 843: mtip_check_surprise_removal in mtip_handle_irq drivers/block/mtip32xx/mtip32xx.c, 879: mtip_handle_irq in mtip_irq_handler (interrupt handler) [FUNC] usleep_range drivers/pci/dwc/pcie-designware.c, 181: usleep_range in dw_pcie_prog_outbound_atu drivers/pci/dwc/pcie-designware-host.c, 479: dw_pcie_prog_outbound_atu in dw_pcie_rd_other_conf drivers/pci/dwc/pcie-designware-host.c, 561: dw_pcie_rd_other_conf in dw_pcie_rd_conf drivers/pci/access.c, 66: [FUNC_PTR]dw_pcie_rd_conf in pci_bus_read_config_word drivers/pci/access.c, 918: pci_bus_read_config_word in pci_read_config_word drivers/gpu/vga/vgaarb.c, 645: pci_read_config_word in vga_arbiter_add_pci_device drivers/gpu/vga/vgaarb.c, 629: _raw_spin_lock_irqsave in vga_arbiter_add_pci_device [FUNC] usleep_range drivers/pci/dwc/pcie-designware.c, 181: usleep_range in dw_pcie_prog_outbound_atu drivers/pci/dwc/pcie-designware-host.c, 479: dw_pcie_prog_outbound_atu in dw_pcie_rd_other_conf drivers/pci/dwc/pcie-designware-host.c, 561: dw_pcie_rd_other_conf in dw_pcie_rd_conf drivers/pci/access.c, 66: [FUNC_PTR]dw_pcie_rd_conf in pci_bus_read_config_word drivers/pci/access.c, 918: pci_bus_read_config_word in pci_read_config_word drivers/pci/ats.c, 139: pci_read_config_word in pci_ats_queue_depth drivers/iommu/intel-iommu.c, 1519: pci_ats_queue_depth in iommu_enable_dev_iotlb drivers/iommu/intel-iommu.c, 5295: iommu_enable_dev_iotlb in intel_iommu_enable_pasid drivers/iommu/intel-iommu.c, 5241: _raw_spin_lock_irqsave in intel_iommu_enable_pasid To fix this bug, usleep_range() is replaced with udelay(). This bug is found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> --- drivers/pci/controller/dwc/pcie-designware.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 778c4f76a884..7f50f7e51543 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -135,7 +135,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, int index, if (val & PCIE_ATU_ENABLE) return; - usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX); + udelay(LINK_WAIT_IATU_MAX); } dev_err(pci->dev, "Outbound iATU is not being enabled\n"); } -- 2.17.0
