From 67effe8fff32f60bdf51cba484766ba6003005bb Mon Sep 17 00:00:00 2001 From: Len Brown Date: Thu, 26 Jul 2007 00:50:06 -0400 Subject: [PATCH] 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 --- Documentation/kernel-parameters.txt | 2 ++ drivers/acpi/tables/tbxface.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+) 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: ,... + 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);