PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB
authorBjorn Helgaas <bhelgaas@google.com>
Thu, 5 Jan 2012 21:27:24 +0000 (14:27 -0700)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 26 Jan 2012 00:13:21 +0000 (16:13 -0800)
commit eb31aae8cb5eb54e234ed2d857ddac868195d911 upstream.

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 [d0000000dfffffff]
  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
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

No differences found