[CPUFREQ] Create a blacklist for processors that should not load the acpi-cpufreq...

[net-next-2.6.git] / arch / x86 / kernel / cpu / cpufreq / acpi-cpufreq.c

diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index ae9b503220cafa62e818afd4bfcf3b849a86c4b3..badce5084060c12074ae615858a489feec610311 100644 (file)
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -588,6 +588,21 @@ static const struct dmi_system_id sw_any_bug_dmi_table[] = {
        },
        { }
 };
+
+static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
+{
+       /* http://www.intel.com/Assets/PDF/specupdate/314554.pdf
+        * AL30: A Machine Check Exception (MCE) Occurring during an
+        * Enhanced Intel SpeedStep Technology Ratio Change May Cause
+        * Both Processor Cores to Lock Up when HT is enabled*/
+       if (c->x86_vendor == X86_VENDOR_INTEL) {
+               if ((c->x86 == 15) &&
+                   (c->x86_model == 6) &&
+                   (c->x86_mask == 8) && smt_capable())
+                       return -ENODEV;
+               }
+       return 0;
+}
 #endif
 
 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
@@ -602,6 +617,12 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 
        dprintk("acpi_cpufreq_cpu_init\n");
 
+#ifdef CONFIG_SMP
+       result = acpi_cpufreq_blacklist(c);
+       if (result)
+               return result;
+#endif
+
        data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;