[PATCH 2/2] x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1
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From: Bjorn Helgaas on 25 Mar 2010 11:30 Yanko's GA-MA78GM-S2H (BIOS F11) reports the following resource in a PCI host bridge _CRS: [07] 32-Bit DWORD Address Space Resource Min Relocatability : MinFixed Max Relocatability : MaxFixed Address Minimum : CFF00000 (_MIN) Address Maximum : FEBFFFFF (_MAX) Address Length : 3EE10000 (_LEN) This is invalid per spec (ACPI 4.0, 6.4.3.5) because it's a fixed size, fixed location descriptor, but _LEN != _MAX - _MIN + 1. Based on https://bugzilla.kernel.org/show_bug.cgi?id=15480#c15, I think Windows handles this by truncating the window so it fits between _MIN and _MAX. I also verified this by modifying the SeaBIOS DSDT and booting Windows 2008 R2 with qemu. This patch makes Linux truncate the window, too, which fixes: http://bugzilla.kernel.org/show_bug.cgi?id=15480 Signed-off-by: Bjorn Helgaas <bjorn.helgaas(a)hp.com> Tested-by: Yanko Kaneti <yaneti(a)declera.com> --- arch/x86/pci/acpi.c | 13 ++++++++++++- 1 files changed, 12 insertions(+), 1 deletions(-) diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index 75ac3f8..e311602 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -123,7 +123,7 @@ setup_resource(struct acpi_resource *acpi_res, void *data) acpi_status status; unsigned long flags; struct resource *root, *conflict; - u64 start, end; + u64 start, end, max_len; status = resource_to_addr(acpi_res, &addr); if (!ACPI_SUCCESS(status)) @@ -140,6 +140,17 @@ setup_resource(struct acpi_resource *acpi_res, void *data) } else return AE_OK; + max_len = addr.maximum - addr.minimum + 1; + if (addr.address_length > max_len) { + dev_printk(KERN_DEBUG, &info->bridge->dev, + "host bridge window length %#llx doesn't fit in " + "%#llx-%#llx, trimming\n", + (unsigned long long) addr.address_length, + (unsigned long long) addr.minimum, + (unsigned long long) addr.maximum); + addr.address_length = max_len; + } + start = addr.minimum + addr.translation_offset; end = start + addr.address_length - 1; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |