src/patches/suse-2.6.27.39/patches.arch/x86_cpufreq_intel_blacklist.patch

   1 From: Prarit Bhargava <prarit@redhat.com>
   2 Subject: [CPUFREQ] Create a blacklist for processors that should not load the acpi-cpufreq module.
   3 References: bnc#542505
   4 Patch-Mainline: yes
   5 Commit-ID: 1a8e42fa81e62d47cc471f7764f906bb42b27a54
   6
   7 Signed-off-by: Thomas Renninger <trenn@suse.de>
   8
   9 Create a blacklist for processors that should not load the acpi-cpufreq module.
  10
  11 The initial entry in the blacklist function is the Intel 0f68 processor.  It's
  12 specification update mentions errata AL30 which implies that cpufreq should not
  13 run on this processor.
  14
  15 Signed-off-by: Prarit Bhargava <prarit@redhat.com>
  16 Signed-off-by: Dave Jones <davej@redhat.com>
  17
  18 diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
  19 index ae9b503..badce50 100644
  20 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
  21 +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
  22 @@ -588,6 +588,21 @@ static const struct dmi_system_id sw_any_bug_dmi_table[] = {
  23         },
  24         { }
  25  };
  26 +
  27 +static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
  28 +{
  29 +       /* http://www.intel.com/Assets/PDF/specupdate/314554.pdf
  30 +        * AL30: A Machine Check Exception (MCE) Occurring during an
  31 +        * Enhanced Intel SpeedStep Technology Ratio Change May Cause
  32 +        * Both Processor Cores to Lock Up when HT is enabled*/
  33 +       if (c->x86_vendor == X86_VENDOR_INTEL) {
  34 +               if ((c->x86 == 15) &&
  35 +                   (c->x86_model == 6) &&
  36 +                   (c->x86_mask == 8) && smt_capable())
  37 +                       return -ENODEV;
  38 +               }
  39 +       return 0;
  40 +}
  41  #endif
  42
  43  static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
  44 @@ -602,6 +617,12 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
  45
  46         dprintk("acpi_cpufreq_cpu_init\n");
  47
  48 +#ifdef CONFIG_SMP
  49 +       result = acpi_cpufreq_blacklist(c);
  50 +       if (result)
  51 +               return result;
  52 +#endif
  53 +
  54         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
  55         if (!data)
  56                 return -ENOMEM;