PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB
Some Dell BIOSes have MCFG tables that don't report the entire
MMCONFIG area claimed by the chipset. If we move PCI devices into
that claimed-but-unreported area, they don't work.
This quirk reads the AMD MMCONFIG MSRs and adds PNP0C01 resources as
needed to cover the entire area.
Example problem scenario:
BIOS-e820: 00000000cfec5400 - 00000000d4000000 (reserved)
Fam 10h mmconf [d0000000, dfffffff]
PCI: MMCONFIG for domain 0000 [bus 00-3f] at [mem 0xd0000000-0xd3ffffff] (base 0xd0000000)
pnp 00:0c: [mem 0xd0000000-0xd3ffffff]
pci 0000:00:12.0: reg 10: [mem 0xffb00000-0xffb00fff]
pci 0000:00:12.0: no compatible bridge window for [mem 0xffb00000-0xffb00fff]
pci 0000:00:12.0: BAR 0: assigned [mem 0xd4000000-0xd40000ff]
Reported-by: Lisa Salimbas <lisa.salimbas@canonical.com>
Reported-by: <thuban@singularity.fr>
Tested-by: dann frazier <dann.frazier@canonical.com>
References: https://bugzilla.kernel.org/show_bug.cgi?id=31602
References: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/647043
References: https://bugzilla.redhat.com/show_bug.cgi?id=770308
Cc: stable@kernel.org # 2.6.34+
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
1 file changed