PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB (eb31aae8) · Commits · 戴 / test

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>

drivers/pnp/quirks.c

+42 −0

Original line number	Diff line number	Diff line
		@@ -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
		{""}
		};

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