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 <[email protected]>
---
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
