ACPI: add "acpi_no_auto_ssdt" bootparam
"acpi_no_auto_ssdt" prevents Linux from automatically loading
all the SSDTs listed in the RSDT/XSDT.
This is needed for debugging. In particular,
it allows a DSDT override to optionally be a DSDT+SSDT override.
http://bugzilla.kernel.org/show_bug.cgi?id=3774
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/tables/tbxface.c b/drivers/acpi/tables/tbxface.c
index 5b302c4..a9e3331 100644
--- a/drivers/acpi/tables/tbxface.c
+++ b/drivers/acpi/tables/tbxface.c
@@ -52,6 +52,8 @@
/* Local prototypes */
static acpi_status acpi_tb_load_namespace(void);
+static int no_auto_ssdt;
+
/*******************************************************************************
*
* FUNCTION: acpi_allocate_root_table
@@ -536,6 +538,10 @@
ACPI_INFO((AE_INFO, "Table DSDT replaced by host OS"));
acpi_tb_print_table_header(0, table);
+
+ if (no_auto_ssdt == 0) {
+ printk(KERN_WARNING "ACPI: DSDT override uses original SSDTs unless \"acpi_no_auto_ssdt\"");
+ }
}
status =
@@ -577,6 +583,11 @@
continue;
}
+ if (no_auto_ssdt) {
+ printk(KERN_WARNING "ACPI: SSDT ignored due to \"acpi_no_auto_ssdt\"\n");
+ continue;
+ }
+
/* Ignore errors while loading tables, get as many as possible */
(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
@@ -622,3 +633,15 @@
}
ACPI_EXPORT_SYMBOL(acpi_load_tables)
+
+
+static int __init acpi_no_auto_ssdt_setup(char *s) {
+
+ printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
+
+ no_auto_ssdt = 1;
+
+ return 1;
+}
+
+__setup("acpi_no_auto_ssdt", acpi_no_auto_ssdt_setup);