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authorLv Zheng <lv.zheng@intel.com>2014-01-08 13:43:40 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-01-08 15:31:36 +0100
commitfab4610583855d544394320d47fccb43305a6398 (patch)
treeff0e09aec798612f32dd0be6fb7f29b586d99c87 /drivers/acpi
parent671cc68dc61f029d44b43a681356078e02d8dab8 (diff)
ACPICA: Cleanup the option of forcing the use of the RSDT.
This change adds a runtime option that will force ACPICA to use the RSDT instead of the XSDT. Although the ACPI spec requires that an XSDT be used instead of the RSDT, the XSDT has been found to be corrupt or ill-formed on some machines. This option is already in the Linux kernel. When it is back ported to ACPICA, code is re-written to follow ACPICA coding style. This patch is the generation of the integration. Signed-off-by: Lv Zheng <lv.zheng@intel.com> Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/acpica/acglobal.h8
-rw-r--r--drivers/acpi/acpica/tbutils.c10
2 files changed, 13 insertions, 5 deletions
diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index e9f1fc7f99c..cffb45742aa 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -119,6 +119,14 @@ bool ACPI_INIT_GLOBAL(acpi_gbl_enable_aml_debug_object, FALSE);
u8 ACPI_INIT_GLOBAL(acpi_gbl_copy_dsdt_locally, FALSE);
/*
+ * Optionally ignore an XSDT if present and use the RSDT instead.
+ * Although the ACPI specification requires that an XSDT be used instead
+ * of the RSDT, the XSDT has been found to be corrupt or ill-formed on
+ * some machines. Default behavior is to use the XSDT if present.
+ */
+u8 ACPI_INIT_GLOBAL(acpi_gbl_do_not_use_xsdt, FALSE);
+
+/*
* Optionally truncate I/O addresses to 16 bits. Provides compatibility
* with other ACPI implementations. NOTE: During ACPICA initialization,
* this value is set to TRUE if any Windows OSI strings have been
diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
index ee6067062cd..6412d3c301c 100644
--- a/drivers/acpi/acpica/tbutils.c
+++ b/drivers/acpi/acpica/tbutils.c
@@ -478,10 +478,10 @@ acpi_status __init acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
ACPI_CAST_PTR(struct acpi_table_header,
rsdp));
- /* Differentiate between RSDT and XSDT root tables */
+ /* Use XSDT if present and not overridden. Otherwise, use RSDT */
- if ((rsdp->revision > 1) && rsdp->xsdt_physical_address
- && !acpi_rsdt_forced) {
+ if ((rsdp->revision > 1) &&
+ rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) {
/*
* RSDP contains an XSDT (64-bit physical addresses). We must use
* the XSDT if the revision is > 1 and the XSDT pointer is present,
@@ -503,8 +503,8 @@ acpi_status __init acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp));
/*
- * If it is present, validate the XSDT for access/size and ensure
- * that all table entries are at least non-NULL
+ * If it is present and used, validate the XSDT for access/size
+ * and ensure that all table entries are at least non-NULL
*/
if (table_entry_size == ACPI_XSDT_ENTRY_SIZE) {
status = acpi_tb_validate_xsdt(address);