ACPI: Disable MWAIT via DMI on broken Compal board

If a system matches in this DMI table,
Linux will disable MWAIT support for idle.
ie. "idle=nomwait" is automatically invoked
and C1_FFH and C2C3_FFH access mode are disabled.

http://bugzilla.kernel.org/show_bug.cgi?id=10807
http://bugzilla.kernel.org/show_bug.cgi?id=10914

Signed-off-by: Zhao Yakui <[email protected]>
Signed-off-by: Li Shaohua <[email protected]>
Signed-off-by: Len Brown <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>

Author: yakuizhao

drivers/acpi/processor_core.c

@@ -120,6 +120,29 @@ static const struct file_operations acpi_processor_info_fops = {
 
 DEFINE_PER_CPU(struct acpi_processor *, processors);
 struct acpi_processor_errata errata __read_mostly;
+static int set_no_mwait(const struct dmi_system_id *id)
+{
+	printk(KERN_NOTICE PREFIX "%s detected - "
+		"disable mwait for CPU C-stetes\n", id->ident);
+	idle_nomwait = 1;
+	return 0;
+}
+
+static struct dmi_system_id __cpuinitdata processor_idle_dmi_table[] = {
+	{
+	set_no_mwait, "IFL91 board", {
+	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
+	DMI_MATCH(DMI_SYS_VENDOR, "ZEPTO"),
+	DMI_MATCH(DMI_PRODUCT_VERSION, "3215W"),
+	DMI_MATCH(DMI_BOARD_NAME, "IFL91") }, NULL},
+	{
+	set_no_mwait, "Extensa 5220", {
+	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
+	DMI_MATCH(DMI_SYS_VENDOR, "ACER"),
+	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
+	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
+	{},
+};
 
 /* --------------------------------------------------------------------------
                                 Errata Handling
@@ -1100,6 +1123,11 @@ static int __init acpi_processor_init(void)
 		return -ENOMEM;
 	acpi_processor_dir->owner = THIS_MODULE;
 
+	/*
+	 * Check whether the system is DMI table. If yes, OSPM
+	 * should not use mwait for CPU-states.
+	 */
+	dmi_check_system(processor_idle_dmi_table);
 	result = cpuidle_register_driver(&acpi_idle_driver);
 	if (result < 0)
 		goto out_proc;