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)
committerJesse Barnes <jbarnes@virtuousgeek.org>
Fri, 6 Jan 2012 20:11:20 +0000 (12:11 -0800)
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
Cc: stable@kernel.org # 2.6.34+
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
drivers/pnp/quirks.c

index dfbd5a6..258fef2 100644 (file)
@@ -295,6 +295,45 @@ static void quirk_system_pci_resources(struct pnp_dev *dev)
        }
 }
 
+#ifdef CONFIG_AMD_NB
+
+#include <asm/amd_nb.h>
+
+static void quirk_amd_mmconfig_area(struct pnp_dev *dev)
+{
+       resource_size_t start, end;
+       struct pnp_resource *pnp_res;
+       struct resource *res;
+       struct resource mmconfig_res, *mmconfig;
+
+       mmconfig = amd_get_mmconfig_range(&mmconfig_res);
+       if (!mmconfig)
+               return;
+
+       list_for_each_entry(pnp_res, &dev->resources, list) {
+               res = &pnp_res->res;
+               if (res->end < mmconfig->start || res->start > mmconfig->end ||
+                   (res->start == mmconfig->start && res->end == mmconfig->end))
+                       continue;
+
+               dev_info(&dev->dev, FW_BUG
+                        "%pR covers only part of AMD MMCONFIG area %pR; adding more reservations\n",
+                        res, mmconfig);
+               if (mmconfig->start < res->start) {
+                       start = mmconfig->start;
+                       end = res->start - 1;
+                       pnp_add_mem_resource(dev, start, end, 0);
+               }
+               if (mmconfig->end > res->end) {
+                       start = res->end + 1;
+                       end = mmconfig->end;
+                       pnp_add_mem_resource(dev, start, end, 0);
+               }
+               break;
+       }
+}
+#endif
+
 /*
  *  PnP Quirks
  *  Cards or devices that need some tweaking due to incomplete resource info
@@ -322,6 +361,9 @@ static struct pnp_fixup pnp_fixups[] = {
        /* PnP resources that might overlap PCI BARs */
        {"PNP0c01", quirk_system_pci_resources},
        {"PNP0c02", quirk_system_pci_resources},
+#ifdef CONFIG_AMD_NB
+       {"PNP0c01", quirk_amd_mmconfig_area},
+#endif
        {""}
 };