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Bjorn Helgaas authored
This DMI quirk turns on "pci=use_crs" for the ALiveSATA2-GLAN because amd_bus.c doesn't handle this system correctly. The system has a single HyperTransport I/O chain, but has two PCI host bridges to buses 00 and 80. amd_bus.c learns the MMIO range associated with buses 00-ff and that this range is routed to the HT chain hosted at node 0, link 0: bus: [00, ff] on node 0 link 0 bus: 00 index 1 [mem 0x80000000-0xfcffffffff] This includes the address space for both bus 00 and bus 80, and amd_bus.c assumes it's all routed to bus 00. We find device 80:01.0, which BIOS left in the middle of that space, but we don't find a bridge from bus 00 to bus 80, so we conclude that 80:01.0 is unreachable from bus 00, and we move it from the original, working, address to something outside the bus 00 aperture, which does not work: pci 0000:80:01.0: reg 10: [mem 0xfebfc000-0xfebfffff 64bit] pci 0000:80:01.0: BAR 0: assigned [mem 0xfd00000000-0xfd00003fff 64bit] The BIOS told us everything we need to know to handle this correctly, so we're better off if we just pay attention, which lets us leave the 80:01.0 device at the original, working, address: ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-7f]) pci_root PNP0A03:00: host bridge window [mem 0x80000000-0xff37ffff] ACPI: PCI Root Bridge [PCI1] (domain 0000 [bus 80-ff]) pci_root PNP0A08:00: host bridge window [mem 0xfebfc000-0xfebfffff] This was a regression between 2.6.33 and 2.6.34. In 2.6.33, amd_bus.c was used only when we found multiple HT chains. 3e3da00c, which enabled amd_bus.c even on systems with a single HT chain, caused this failure. This quirk was written by Graham. If we ever enable "pci=use_crs" for machines from 2006 or earlir, this quirk should be removed. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=16007 Cc: stable@kernel.org Reported-by: Graham Ramsey <ramsey.graham@ntlworld.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
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