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authorLen Brown <len.brown@intel.com>2007-07-26 00:50:06 -0400
committerLen Brown <len.brown@intel.com>2007-07-26 00:50:06 -0400
commit67effe8fff32f60bdf51cba484766ba6003005bb (patch)
tree8f8bf5ea5d7ddd1679c8a7d46c7219770d7cdaf8
parente4903fb59590f86190280a549420f6cb85bd7f7e (diff)
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>
-rw-r--r--Documentation/kernel-parameters.txt2
-rw-r--r--drivers/acpi/tables/tbxface.c23
2 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fb80e9ffea68..379931e74334 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -166,6 +166,8 @@ and is between 256 and 4096 characters. It is defined in the file
acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
Format: <irq>,<irq>...
+ acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
+
acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
Format: To spoof as Windows 98: ="Microsoft Windows"
diff --git a/drivers/acpi/tables/tbxface.c b/drivers/acpi/tables/tbxface.c
index 5b302c4e293f..a9e3331fee5d 100644
--- a/drivers/acpi/tables/tbxface.c
+++ b/drivers/acpi/tables/tbxface.c
@@ -52,6 +52,8 @@ ACPI_MODULE_NAME("tbxface")
/* Local prototypes */
static acpi_status acpi_tb_load_namespace(void);
+static int no_auto_ssdt;
+
/*******************************************************************************
*
* FUNCTION: acpi_allocate_root_table
@@ -536,6 +538,10 @@ static acpi_status acpi_tb_load_namespace(void)
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 @@ static acpi_status acpi_tb_load_namespace(void)
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_status acpi_load_tables(void)
}
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);