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>
This commit is contained in:
Len Brown 2007-07-26 00:50:06 -04:00
parent e4903fb595
commit 67effe8fff
2 changed files with 25 additions and 0 deletions

View File

@ -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"

View File

@ -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);