From: Zhao Yakui <yakui.zhao@xxxxxxxxx> On some boxes there exist both RSDT and XSDT table. But unfortunately sometimes there exists the following error when XSDT table is used: a. 32/64X address mismatch b. The 32/64X FACS address mismatch In such case the boot option of "acpi=rsdt" is provided so that RSDT is tried instead of XSDT table when the system can't work well. http://bugzilla.kernel.org/show_bug.cgi?id=8246 Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx> cc:Thomas Renninger <trenn@xxxxxxx> --- Documentation/kernel-parameters.txt | 2 ++ arch/ia64/kernel/acpi.c | 1 + arch/x86/kernel/acpi/boot.c | 6 +++++- drivers/acpi/tables/tbutils.c | 3 ++- include/acpi/acpixf.h | 1 + 5 files changed, 11 insertions(+), 2 deletions(-) Index: linux-2.6/arch/x86/kernel/acpi/boot.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/acpi/boot.c +++ linux-2.6/arch/x86/kernel/acpi/boot.c @@ -47,7 +47,7 @@ #endif static int __initdata acpi_force = 0; - +u32 acpi_rsdt_forced; #ifdef CONFIG_ACPI int acpi_disabled = 0; #else @@ -1783,6 +1783,10 @@ static int __init parse_acpi(char *arg) disable_acpi(); acpi_ht = 1; } + /* acpi=rsdt use RSDT instead of XSDT */ + else if (strcmp(arg, "rsdt") == 0) { + acpi_rsdt_forced = 1; + } /* "acpi=noirq" disables ACPI interrupt routing */ else if (strcmp(arg, "noirq") == 0) { acpi_noirq_set(); Index: linux-2.6/include/acpi/acpixf.h =================================================================== --- linux-2.6.orig/include/acpi/acpixf.h +++ linux-2.6/include/acpi/acpixf.h @@ -48,6 +48,7 @@ #include "actypes.h" #include "actbl.h" +extern u32 acpi_rsdt_forced; /* * Global interfaces */ Index: linux-2.6/drivers/acpi/tables/tbutils.c =================================================================== --- linux-2.6.orig/drivers/acpi/tables/tbutils.c +++ linux-2.6/drivers/acpi/tables/tbutils.c @@ -420,7 +420,8 @@ acpi_tb_parse_root_table(acpi_physical_a /* Differentiate between RSDT and XSDT root tables */ - if (rsdp->revision > 1 && rsdp->xsdt_physical_address) { + if (rsdp->revision > 1 && rsdp->xsdt_physical_address + && !acpi_rsdt_forced) { /* * Root table is an XSDT (64-bit physical addresses). We must use the * XSDT if the revision is > 1 and the XSDT pointer is present, as per Index: linux-2.6/arch/ia64/kernel/acpi.c =================================================================== --- linux-2.6.orig/arch/ia64/kernel/acpi.c +++ linux-2.6/arch/ia64/kernel/acpi.c @@ -65,6 +65,7 @@ EXPORT_SYMBOL(pm_idle); void (*pm_power_off) (void); EXPORT_SYMBOL(pm_power_off); +u32 acpi_rsdt_forced; unsigned int acpi_cpei_override; unsigned int acpi_cpei_phys_cpuid; Index: linux-2.6/Documentation/kernel-parameters.txt =================================================================== --- linux-2.6.orig/Documentation/kernel-parameters.txt +++ linux-2.6/Documentation/kernel-parameters.txt @@ -139,6 +139,8 @@ and is between 256 and 4096 characters. ht -- run only enough ACPI to enable Hyper Threading strict -- Be less tolerant of platforms that are not strictly ACPI specification compliant. + rsdt -- RSDT is used instead of XSDT table when both + exits. See also Documentation/power/pm.txt, pci=noacpi -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
