diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c
index 30e4dc0..f336437 100644 (file)
--- a/drivers/acpi/processor_pdc.c
+++ b/drivers/acpi/processor_pdc.c
@@ -1,5 +1,6 @@
 #include <acpi/acpi_drivers.h>
 #include <acpi/processor.h>
+#include <linux/dmi.h>
 
 #define PREFIX                 "ACPI: "
 #define _COMPONENT             ACPI_PROCESSOR_COMPONENT
@@ -144,6 +145,29 @@
 }
 EXPORT_SYMBOL_GPL(acpi_processor_set_pdc);
 
+static int early_pdc_optin;
+static int set_early_pdc_optin(const struct dmi_system_id *id)
+{
+       early_pdc_optin = 1;
+       return 0;
+}
+
+static struct dmi_system_id __cpuinitdata early_pdc_optin_table[] = {
+       {
+       set_early_pdc_optin, "HP Envy", {
+       DMI_MATCH(DMI_BIOS_VENDOR, "Hewlett-Packard"),
+       DMI_MATCH(DMI_PRODUCT_NAME, "HP Envy") }, NULL},
+       {
+       set_early_pdc_optin, "HP Pavilion dv6", {
+       DMI_MATCH(DMI_BIOS_VENDOR, "Hewlett-Packard"),
+       DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv6") }, NULL},
+       {
+       set_early_pdc_optin, "HP Pavilion dv7", {
+       DMI_MATCH(DMI_BIOS_VENDOR, "Hewlett-Packard"),
+       DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv7") }, NULL},
+       {},
+};
+
 static acpi_status
 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
+       /*
+        * Allow systems to opt-in to early _PDC evaluation.
+        */
+       dmi_check_system(early_pdc_optin_table);
+       if (!early_pdc_optin)
+               return;
+
        acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
                            ACPI_UINT32_MAX,
                            early_init_pdc, NULL, NULL);