On Mon, 2013-02-04 at 10:36 -0800, Stephen Hemminger wrote: > > I think drivers/pci/search.c is identical between 3.7 and 3.8-rc1. Is > > this the first time you've turned on the IOMMU on that box? > > It exists in 3.7 and earlier kernels, just haven't turned on same config. > > > It's the same warning as in this bugzilla: > > https://bugzilla.kernel.org/show_bug.cgi?id=44881, and there's a patch > > there at https://bugzilla.kernel.org/show_bug.cgi?id=44881#c11, but > > it's just a quirk that turns off VT-d if we find certain broken > > bridges. It doesn't look like you have any of those (although I don't > > know what you have at 05:00.0). > > > > Bjorn > > This is a standard ASUS motherboard, and don't want to disable VT-d. Stephen, Can you give the lspci -vvv of device 5:00.0 to see if it's one we've seen before? Does the patch below help? Bjorn, I think we need to quirk it somehow. So far they've all been PCI-to-PCI bridges attached to root ports where we expect it's actually a PCIe-to-PCI bridge. Seems like maybe we could have the same attached to a downstream port. The patch below avoids the WARN and gives us a device, but of course pci_is_pcie reports wrong for this device and may cause some trickle down breakage. A more complete option might be to add a is_pcie flag to the device that can be set independent of pcie_cap. We'd need to check all the callers for assumptions, but then we could put the quirk in one place and hopefully fix everything. Thoughts? Thanks, Alex diff --git a/drivers/pci/search.c b/drivers/pci/search.c index bf969ba..65ae270 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -42,6 +42,15 @@ pci_find_upstream_pcie_bridge(struct pci_dev *pdev) } /* PCI device should connect to a PCIe bridge */ if (pci_pcie_type(pdev) != PCI_EXP_TYPE_PCI_BRIDGE) { + /* + * Not all PCIe-to-PCI bridges expose a PCIe + * capability. If we make it to a PCIe root port + * and the previous device was a PCI-to-PCI bridge, + * assume it was really a PCIe-to-PCI bridge. + */ + if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT && + tmp && tmp->hdr_type == PCI_HEADER_TYPE_BRIDGE) + return tmp; /* Busted hardware? */ WARN_ON_ONCE(1); return NULL; -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
