Hi Jia, On 02/09/2018 04:38, Jia-Ju Bai wrote: > 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); You might use the mdelay instead of udelay, however this fix and others were already made on patch on [1] [1] https://lkml.org/lkml/2018/9/10/284 Regards, Gustavo > } > dev_err(pci->dev, "Outbound iATU is not being enabled\n"); > } >
