some BIOS only let AMD fam 10h handle bus0, and nvidia mcp55/ck804 to handle other buses. at that case MCFG will cover all over them.
but with acpi=off, we can not use MCFG. this patch will double check the busnbits, and if it is less handling 256 bues, and acpi=off will forcely reset the mmconf in msr, so we still use mmconf in above case. Signed-off-by: Yinghai Lu <[EMAIL PROTECTED]> Index: linux-2.6/arch/x86/kernel/setup_64.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/setup_64.c +++ linux-2.6/arch/x86/kernel/setup_64.c @@ -720,14 +720,21 @@ static void __cpuinit fam10h_check_enabl /* try to make sure that AP's setting is identical to BSP setting */ if (val & FAM10H_MMIO_CONF_ENABLE) { - u64 base; - base = val & (0xffffULL << 32); - if (fam10h_pci_mmconf_base_status <= 0) { - fam10h_pci_mmconf_base = base; - fam10h_pci_mmconf_base_status = 1; - return; - } else if (fam10h_pci_mmconf_base == base) - return; + unsigned busnbits; + busnbits = (val >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) & + FAM10H_MMIO_CONF_BUSRANGE_MASK; + + /* only trust the one handle 256 buses, if acpi=off */ + if (!acpi_pci_disabled || busnbits >= 8) { + u64 base; + base = val & (0xffffULL << 32); + if (fam10h_pci_mmconf_base_status <= 0) { + fam10h_pci_mmconf_base = base; + fam10h_pci_mmconf_base_status = 1; + return; + } else if (fam10h_pci_mmconf_base == base) + return; + } } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/