ACPICA: Add option to disable loading of SSDTs from the RSDT/XSDT

Optionally do not load any SSDTs from the RSDT/XSDT during
initialization.  This can be useful for overriding SSDTs
using DSDT overriding, thus useful for debugging ACPI
problems on some machines.  Lv Zheng. ACPICA BZ 1005.

References: https://bugs.acpica.org/show_bug.cgi?id=1005
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>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index e72186340fec..da6b6634e5b3 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -1715,6 +1715,17 @@ acpi_status acpi_os_release_object(acpi_cache_t * cache, void *object)
 }
 #endif
 
+static int __init acpi_no_auto_ssdt_setup(char *s)
+{
+        printk(KERN_NOTICE PREFIX "SSDT auto-load disabled\n");
+
+        acpi_gbl_disable_ssdt_table_load = TRUE;
+
+        return 1;
+}
+
+__setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);
+
 acpi_status __init acpi_os_initialize(void)
 {
         acpi_os_map_generic_address(&acpi_gbl_FADT.xpm1a_event_block);