Imported linux-2.6.27.39 suse/xen patches.

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.39 / patches.arch / acpi_thinkpad_introduce_acpi_root_table_boot_param.patch

From: Thomas Renninger <trenn@suse.de>
Subject: Introduce acpi_root_table=rsdt boot param and dmi list to force rsdt
Patch-mainline: not yet
References: http://bugzilla.kernel.org/show_bug.cgi?id=8246

This one is part of a patch series:
acpi_thinkpad_introduce_acpi_root_table_boot_param.patch
acpi_thinkpad_introduce_acpica_rsdt_global_variable.patch
acpi_thinkpad_remove_R40e_c-state_blacklist.patch

Blacklist R40e, R51e and T40, T40p, T41, T41p, T42, T42p, R50 and R50p
ThinkPads to use the RSDT instead of the XSDT.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Tested-by: Mark Doughty <me@markdoughty.co.uk>
CC: Yakui Zhao <yakui.zhao@intel.com>

---
 Documentation/kernel-parameters.txt |    5 ++++
 drivers/acpi/tables.c               |   37 ++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -237,6 +237,11 @@ and is between 256 and 4096 characters. 
 			to assume that this machine's pmtimer latches its value
 			and always returns good values.
 
+	acpi_root_table= [X86,ACPI]
+			{ rsdt }
+			rsdt: Take RSDT address for fetching
+			ACPI tables (instead of XSDT)
+
 	agp=		[AGP]
 			{ off | try_unsupported }
 			off: disable AGP support
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -32,6 +32,7 @@
 #include <linux/errno.h>
 #include <linux/acpi.h>
 #include <linux/bootmem.h>
+#include <linux/dmi.h>
 
 #define PREFIX			"ACPI: "
 
@@ -282,6 +283,37 @@ static void __init check_multiple_madt(v
 	return;
 }
 
+static struct dmi_system_id __initdata acpi_rsdt_dmi_table[] = {
+	{
+	    .ident = "ThinkPad ", /* R40e, broken C-states */
+	    .matches = {
+		DMI_MATCH(DMI_BIOS_VENDOR, "IBM"),
+		DMI_MATCH(DMI_BIOS_VERSION, "1SET")},
+	},
+	{
+	    .ident = "ThinkPad ", /* R50e, slow booting */
+	    .matches = {
+		DMI_MATCH(DMI_BIOS_VENDOR, "IBM"),
+		DMI_MATCH(DMI_BIOS_VERSION, "1WET")},
+	},
+	{
+	    .ident = "ThinkPad ", /* T40, T40p, T41, T41p, T42, T42p
+				     R50, R50p */
+	    .matches = {
+		DMI_MATCH(DMI_BIOS_VENDOR, "IBM"),
+		DMI_MATCH(DMI_BIOS_VERSION, "1RET")},
+	},
+	{}
+};
+
+static int __init acpi_force_rsdt(char *opt)
+{
+	if (!strcmp(opt, "rsdt"))
+		acpi_gbl_force_rsdt = 1;
+	return 0;
+}
+early_param("acpi_root_table", acpi_force_rsdt);
+
 /*
  * acpi_table_init()
  *
@@ -295,6 +327,11 @@ int __init acpi_table_init(void)
 {
 	acpi_status status;
 
+	if (dmi_check_system(acpi_rsdt_dmi_table))
+		acpi_gbl_force_rsdt = 1;
+	if (acpi_gbl_force_rsdt)
+		printk(KERN_INFO "Using RSDT as ACPI root table\n");
+
 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
 	if (ACPI_FAILURE(status))
 		return 1;