Messages in this thread Patch in this message | | | From | Jacob Pan <> | Subject | [PATCH] x86/pci/mrst: add extra check in fixed bar detection | Date | Fri, 16 Jul 2010 11:58:26 -0700 |
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Fixed bar capability structure is searched in PCI extended configuration space. We need to make sure there is a valid capability id to begin with otherwise, the search code may stuck in a infinite loop which results in boot hang. This patch adds additional check for cap ID 0, which is also invalid.
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> --- arch/x86/pci/mrst.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/x86/pci/mrst.c b/arch/x86/pci/mrst.c index c9649d0..8636567 100644 --- a/arch/x86/pci/mrst.c +++ b/arch/x86/pci/mrst.c @@ -66,8 +66,9 @@ static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn) devfn, pos, 4, &pcie_cap)) return 0; - if (pcie_cap == 0xffffffff) - return 0; + if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 || + PCI_EXT_CAP_ID(pcie_cap) == 0xffff) + break; if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) { raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, @@ -76,7 +77,7 @@ static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn) return pos; } - pos = pcie_cap >> 20; + pos = PCI_EXT_CAP_NEXT(pcie_cap); } return 0; -- 1.7.0.4
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