1 files changed, 9 insertions, 1 deletions

diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c
index f1fa500ac105..1180d536d1eb 100644
--- a/drivers/cpufreq/longhaul.c
+++ b/drivers/cpufreq/longhaul.c
@@ -77,7 +77,7 @@ static unsigned int longhaul_index;
 static int scale_voltage;
 static int disable_acpi_c3;
 static int revid_errata;
-
+static int enable;
 
 /* Clock ratios multiplied by 10 */
 static int mults[32];
@@ -965,6 +965,10 @@ static int __init longhaul_init(void)
         if (!x86_match_cpu(longhaul_id))
                 return -ENODEV;
 
+        if (!enable) {
+                printk(KERN_ERR PFX "Option \"enable\" not set. Aborting.\n");
+                return -ENODEV;
+        }
 #ifdef CONFIG_SMP
         if (num_online_cpus() > 1) {
                 printk(KERN_ERR PFX "More than 1 CPU detected, "
@@ -1021,6 +1025,10 @@ MODULE_PARM_DESC(scale_voltage, "Scale voltage of processor");
  * such. */
 module_param(revid_errata, int, 0644);
 MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID");
+/* By default driver is disabled to prevent incompatible
+ * system freeze. */
+module_param(enable, int, 0644);
+MODULE_PARM_DESC(enable, "Enable driver");
 
 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
 MODULE_DESCRIPTION("Longhaul driver for VIA Cyrix processors.");