On failure pcie_capability_read_*() sets it's last parameter, val to 0. However, with Patch 12/12, it is possible that val is set to ~0 on failure. This would introduces a bug because (x & x) == (~0 & x). Since ~0 is an invalid value in here, Add extra check for ~0 in the if condition to ensure success or failure. Suggested-by: Bjorn Helgaas <bjorn@xxxxxxxxxxx> Signed-off-by: Saheed O. Bolarinwa <refactormyself@xxxxxxxxx> --- drivers/pci/pci-acpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 7224b1e5f2a8..873b005947e4 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -253,7 +253,7 @@ static bool pcie_root_rcb_set(struct pci_dev *dev) return false; pcie_capability_read_word(rp, PCI_EXP_LNKCTL, &lnkctl); - if (lnkctl & PCI_EXP_LNKCTL_RCB) + if ((lnkctl != (u16)~0) && (lnkctl & PCI_EXP_LNKCTL_RCB)) return true; return false; @@ -797,7 +797,7 @@ bool pciehp_is_native(struct pci_dev *bridge) return false; pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap); - if (!(slot_cap & PCI_EXP_SLTCAP_HPC)) + if ((slot_cap == (u32)~0) || !(slot_cap & PCI_EXP_SLTCAP_HPC)) return false; if (pcie_ports_native) -- 2.18.4
