Hi Frank, This is in reference to https://bugzilla.kernel.org/show_bug.cgi?id=52211, which you mentioned on #linux-pci while I was on vacation. An SR-IOV card doesn't work correctly in the x3650 unless we ignore the PCI host bridge _CRS information, either by using an old kernel, booting with "pci=nocrs", or adding a quirk to set pci_use_crs to false automatically. Here's the relevant info from the 3.8.0-rc1 dmesg you attached to the bugzilla: ACPI: PCI Root Bridge [IOH0] (domain 0000 [bus 00-ff]) pci_bus 0000:00: root bus resource [mem 0x3c0700000000-0x3c077fff0000] pci_bus 0000:00: root bus resource [mem 0x3c0780000000-0x3c07ffff0000] pci 0000:00:02.0: PCI bridge to [bus 11-15] pci 0000:00:02.0: bridge window [mem 0x3c0778000000-0x3c07f7ffffff 64bit pref] pci 0000:00:02.0: no compatible bridge window for [mem 0x3c0778000000-0x3c07f7ffffff 64bit pref] pci 0000:11:00.0: [1014:044b] type 00 class 0x120000 pci 0000:11:00.0: reg 10: [mem 0x3c07f0000000-0x3c07f7ffffff 64bit pref] pci 0000:11:00.0: reg 224: [mem 0x3c0778000000-0x3c077fffffff 64bit pref] pci 0000:11:00.0: no compatible bridge window for [mem 0x3c07f0000000-0x3c07f7ffffff 64bit pref] pci 0000:11:00.0: no compatible bridge window for [mem 0x3c0778000000-0x3c07efffffff 64bit pref] The BIOS told us that [mem 0x3c0700000000-0x3c077fff0000] and [mem 0x3c0780000000-0x3c07ffff0000] are routed to PCI bus 0000:00. It doesn't mention the 64KB [mem 0x3c077fff0001-0x3c077fffffff] region between those two apertures, so we have to assume that region is not routed to bus 0000:00. But the BIOS programmed the 00:02.0 bridge window and the 11:00.0 SR-IOV BAR at 0x224 to use that 64KB region. Since the card works with "pci=nocrs", it seems pretty clear that the 64KB hole between the reported apertures actually *is* routed to bus 0000:00. This looks like a BIOS bug. It looks like all the PNP0A08:00 _CRS apertures above 4GB are missing the last 64KB. Using "pci=nocrs" or a quirk like the one in the bugzilla avoids this immediate issue, but it also will keep hot-plug from working because without the _CRS info, we don't know what resources are available to assign to hot-added devices. So it's better to fix the BIOS if you can. Bjorn -- 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
