ACPI: Disable MWAIT via DMI on broken Compal board
Zhao Yakui [Tue, 24 Jun 2008 10:02:57 +0000 (18:02 +0800)]
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 <yakui.zhao@intel.com>
Signed-off-by: Li Shaohua <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

drivers/acpi/processor_core.c

index 4e1bb89..ec0f2d5 100644 (file)
@@ -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;